I don’t think so, the Roblox forum is on the version Version bump to v2.6.0.beta3 · discourse/discourse@2a268bd · GitHub. Since then there have only been two bookmark-related commits which I did, neither of which do anything with the topic bookmark loading or serialization.
https://github.com/discourse/discourse/commit/0d63eb412404330b943f367c4cdbc2021b900995
https://github.com/discourse/discourse/commit/c3cede697dddeacabc6410ff4e4f8425805004cb
There must be some other weird coincidence at play I guess?