HTTP Response Modified Date for Topics

Hi, this is what I mean.

https://meta.discourse.org/t/populating-a-test-database-with-large-number-of-posts-users/38600/3

If I check the Last-Modified header for this old thread from 2016, the Lqst Modified date corresponds to the moment I browsed the website, not to the moment it was last updated:

curl --head https://meta.discourse.org/t/populating-a-test-database-with-large-number-of-posts-users/38600/3
HTTP/1.1 200 OK
Date: Tue, 27 Feb 2018 22:28:19 GMT
Content-Type: text/html
Connection: keep-alive
Server: nginx
Vary: Accept-Encoding
X-Frame-Options: SAMEORIGIN
X-XSS-Protection: 1; mode=block
X-Content-Type-Options: nosniff
X-Discourse-Route: topics/show
Cache-Control: no-store, must-revalidate, no-cache, private
X-Request-Id: b17b8ff0-02db-4d72-8f68-db1deec2e5d9
X-Runtime: 0.025722
Referrer-Policy: no-referrer-when-downgrade
Strict-Transport-Security: max-age=31536000

Is this considered normal behavior?