I expect the announcement URL to be wrong, it should probably be https://kde.org/announcements/gear/21.04.1 . But let's fix that afterwards, when the announcement is actually online.

kate.changes:
* [addons/project/git/gitutils] Add missing include optional to make bsd happy
This was reverted.

kdepim-runtime.changes:
* Adjust the size of the iCal Calendar File properties dialog (kde#435871)
This didn't make it into the 21.04.1 release.

messagelib.changes:
"- Drop 0001-Fix-CVE-2021-31855.patch. Merged upstream." was added to the wrong changelog entry, to the one that actually added the patch.

I'll fix those...

The proper URL seems to be https://kde.org/announcements/releases/21.04.1 (similar to 20.04.3) .
I'll update them...