The plan has always been to try and keep parity with Mozillians. This is obviously a problem Mozilla needs to fix as well. It seems silly to assume that they aren’t already thinking about this now.
What we do need to figure out is a timeline. When do we need to have an alternative decided on so that we can implement it in the sites we control? If EoL is November, is September the deadline? Maybe July for a bit more time?
For Community Ops, this only affects Discourse, yes? We know that many other authentication systems work on Discourse, it’s just the Mozillians API connections that would be disrupted.