Should Re-saving a Blog Post Generate New Image Sizes

I was under the impression that if I re-saved a blog post, any new image sizes that I've declared would be generated?

At the moment, I'm having to re-select the same asset in the asset chooser, and then click save for the new size to be created.

– Toby

Perch: 3.1.1
Production mode: Production (100)
Installed apps: content (3.1.1), assets (3.1.1), categories (3.1.1), perch_blog (5.6.1), perch_forms (1.11)
DB driver: PDO
DB tables: perch2_blog_authors (4), perch2_blog_categories (0), perch2_blog_comments (2705), perch2_blog_index (1119), perch2_blog_posts (38), perch2_blog_posts_to_categories (0), perch2_blog_posts_to_tags (35), perch2_blog_sections (1), perch2_blog_tags (27), perch2_blog_webmention_queue (0), perch2_blogs (1), perch2_categories (0), perch2_category_counts (0), perch2_category_sets (1), perch2_content_index (504), perch2_content_items (292), perch2_content_regions (24), perch2_events (0), perch2_events_categories (0), perch2_events_to_categories (0), perch2_forms (1), perch2_forms_responses (0), perch2_members (1), perch2_members_forms (0), perch2_members_member_tags (1), perch2_members_sessions (1), perch2_members_tags (1), perch2_menu_items (10), perch2_navigation (0), perch2_navigation_pages (0), perch2_page_templates (1), perch2_pages (14), perch2_resource_log (2544), perch2_resource_tags (0), perch2_resources (294), perch2_resources_to_tags (0), perch2_settings (29), perch2_user_passwords (0), perch2_user_privileges (44), perch2_user_role_privileges (23), perch2_user_roles (2), perch2_users (2)
Users: 2
App runtimes:
<?php
    $apps_list = [
        'perch_blog',
        'perch_forms',
    ];
?>
Scheduled tasks for perch_blog: delete_spam_comments (1440 mins), publish_posts (1 mins), process_webmentions (1 mins)
Editor plug-ins:
H1: aba6f4eddc1bda99b4adb4584da46700
L1: 7a3f147222d8eff9c594bb425084af99
F1: 3b606135b33e6a102526838f4152a807
headerColour: #ffffff
content_singlePageEdit: 1
helpURL: https://acehigh.it
siteURL: /
hideBranding: 1
content_collapseList: 0
lang: en-gb
update_2.3.3: done
latest_version:
headerScheme: light
perch_members_login_page: /downloads/login.php?r={returnURL}
perch_events_detail_url: /exhibitions/event.php?event={eventSlug}
perch_blog_post_url: /news/post.php?s={postSlug}
perch_blog_slug_format: %Y-%m-%d-{postTitle}
perch_blog_akismet_key:
perch_blog_comment_notify: 1
perch_blog_max_spam_days: 1
dashboard: 0
content_hideNonEditableRegions: 0
logoPath: /ace/resources/logo.png
perch_events_update: 1.8
perch_blog_update: 5.6
update_2.4.9: done
on_sale_version:
hide_pwd_reset: 0
content_frontend_edit: 0
update_3.1.1: done
PERCH_DEVELOPMENT: 10
PERCH_STAGING: 50
PERCH_PRODUCTION: 100
PERCH_DB_USERNAME: root
PERCH_DB_SERVER: localhost
PERCH_DB_DATABASE: perch_cw_loc
PERCH_DB_PREFIX: perch2_
PERCH_TZ: Europe/London
PERCH_EMAIL_FROM: info@corewire.com
PERCH_EMAIL_FROM_NAME: Corewire
PERCH_LOGINPATH: /admin
PERCH_PATH: /Users/toby/Sites/corewire/admin
PERCH_CORE: /Users/toby/Sites/corewire/admin/core
PERCH_RESFILEPATH: /Users/toby/Sites/corewire/admin/resources
PERCH_RESPATH: /admin/resources
PERCH_HTML5: 1
PERCH_RWD: 1
PERCH_RUNWAY:
PERCH_ERROR_MODE: DIE
PERCH_DATE_LONG: %d %B %Y
PERCH_DATE_SHORT: %d %b %Y
PERCH_TIME_SHORT: %H:%M
PERCH_TIME_LONG: %H:%M:%S
PERCH_RUNWAY_ROUTED:
PERCH_STRONG_PASSWORDS:
PERCH_ASSET_VERSION: 8255e4c4a367cfa3e2bd
PERCH_DEBUG:
PERCH_PREVIEW_ARG: preview
PERCH_TEMPLATE_PATH: /Users/toby/Sites/corewire/admin/templates
PERCH_TEMPLATE_FILTERS:
PERCH_DEFAULT_DOC: index.php
PERCH_DEFAULT_EXT: .php
PERCH_PRODUCTION_MODE: 100
PERCH_XHTML_MARKUP:
PERCH_HTML_ENTITIES:
PERCH_SSL:
PERCH_STRIPSLASHES:
PERCH_PROGRESSIVE_FLUSH: 1
PERCH_PARANOID:
PERCH_FORCE_SECURE_COOKIES:
PERCH_DEFAULT_BUCKET: default
PERCH_TRANSLATION_ASSIST:
PERCH_PASSWORD_MIN_LENGTH: 6
PERCH_MAX_FAILED_LOGINS: 10
PERCH_AUTH_LOCKOUT_DURATION: 1 HOUR
PERCH_VERIFY_UPLOADS:
PERCH_PRIV_ASSIST:
PERCH_CUSTOM_EDITOR_CONFIGS:
PERCH_ENABLE_EXIF: 1
PERCH_AUTH_PLUGIN:
PERCH_DB_CHARSET: utf8
PERCH_DB_PORT:
PERCH_DB_SOCKET:
PERCH_APPS_EDITOR_PLUGIN: markitup
PERCH_APPS_EDITOR_MARKUP_LANGUAGE: markdown
Hosting settings
PHP: 7.2.1
Zend: 3.2.0
OS: Darwin
SAPI: apache2handler
Safe mode: not detected
MySQL client: mysqlnd 5.0.12-dev - 20150407 - $Id: b396954eeb2d1d9ed7902b8bae237b287f21ad9e $
MySQL server: 5.6.38
Free disk space: 95.29 GB
Extensions: Core, date, libxml, openssl, pcre, sqlite3, zlib, bcmath, bz2, calendar, ctype, curl, dom, hash, fileinfo, filter, ftp, gd, SPL, iconv, intl, json, ldap, mbstring, session, standard, mysqlnd, PDO, pdo_mysql, pdo_sqlite, Phar, posix, Reflection, mysqli, SimpleXML, soap, sockets, sodium, exif, tokenizer, wddx, xml, xmlreader, xmlwriter, xsl, zip, apache2handler, imap, gettext, pgsql, pdo_pgsql, igbinary, memcached
GD: Yes
ImageMagick: No
PHP max upload size: 32M
PHP max form post size: 8M
PHP memory limit: 128M
Total max uploadable file size: 8M
Resource folder writeable: Yes
Session timeout: 24 minutes
Native JSON: Yes
Filter functions: Yes
Transliteration functions: Yes
HTTP_HOST: cw.loc:8888
HTTP_CONNECTION: keep-alive
HTTP_UPGRADE_INSECURE_REQUESTS: 1
HTTP_USER_AGENT: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36
HTTP_ACCEPT: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
HTTP_REFERER: https://cw.loc:8888/admin/core/settings/diagnostics/
HTTP_ACCEPT_ENCODING: gzip, deflate
HTTP_ACCEPT_LANGUAGE: en-GB,en-US;q=0.9,en;q=0.8
HTTP_COOKIE: cmsa=1; PHPSESSID=mgvk15ufcn727nh6n6q70r3aqa
PATH: /usr/bin:/bin:/usr/sbin:/sbin
SERVER_SOFTWARE: Apache
SERVER_NAME: cw.loc
SERVER_ADDR: ::1
SERVER_PORT: 8888
REMOTE_ADDR: ::1
DOCUMENT_ROOT: /Users/toby/Sites/corewire
SERVER_ADMIN: you@example.com
SCRIPT_FILENAME: /Users/toby/Sites/corewire/admin/core/settings/diagnostics/index.php
REMOTE_PORT: 58940
GATEWAY_INTERFACE: CGI/1.1
SERVER_PROTOCOL: HTTP/1.1
REQUEST_METHOD: GET
QUERY_STRING: extended
REQUEST_URI: /admin/core/settings/diagnostics/?extended
SCRIPT_NAME: /admin/core/settings/diagnostics/index.php
PHP_SELF: /admin/core/settings/diagnostics/index.php
REQUEST_TIME_FLOAT: 1531297755.636
REQUEST_TIME: 1531297755
argc: 1