The play store app was updated yesterday (30-Sept-2019) so they are there and working.

It does not look like the regular shutdown zendesk page. This is more of a they cancelled it page. Could be migrating, could be something else.

Looking at archive.org there was never much there anyway.

https://web.archive.org/web/20180625194357/https://mycelium-support.zendesk.com/hc/en-us

-Dave