Developers with plugins active on 1M sites or more received an email invitation from Andy Peatling to begin building support for Calypso.

We did? I don't remember ever seeing this (UpdraftPlus, passed 1 million installs 6 months ago). Nothing in my email archive.

Having said that, a search of our support systems shows that no user has ever asked about Calypso support. Only one user has ever mentioned Calypso in any way at all, and that mention was just incidental.