The authentication system for the Hydra Wiki Platform uses 307 and 308 redirects in a few places. Instead of implementing our own redirect code we added this to the base MediaWiki code.
@Alexia Reminder about the CR at https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/425439/3/includes/OutputPage.php
In summary: The existing code seems to unintentionally not apply to 302 (Temporary) and only to 301 and 303. As such, adding 308 (Permanent) seems fine, but 307 (also Temporary) might be problematic, specially for the Last-Modified behaviour which seems is intentionally not applied to temporary redirects.
I would recommend switching the logic around so that the status header is always applied (including for the new 307 and 308 statuses), but keep the lastModified logic only applied to permanent redirects.