Here’s the announcement that a developer posted on Paper’s Discord:
Hi everyone! We are aware that MC 1.15 has been released.
Please exercise patience and understanding over the next few days.
If you only show up to ask for ETAs or otherwise harass the
community you will be removed.
There are no ETAs. There is no expected finish time. There is no
spoon. It'll be ready when it's ready. Anyone telling you anything
else is just making stuff up.
Please feel free to discuss aspects of the release
in the relevant channels. Thanks.
Of course the “relevant channels” doesn’t really apply here in the forums but you get the idea. Hopefully soon, though! My server is waiting on the update too.