This is really a follow-up question to this one, for which only Stack Exchange specific answers were provided.
I set up delegation of authentication to Google, based on this SO answer, specifically because I wanted to be able to swap out authentication providers without having to go to all the individual sites that use the custom URI as the user identifier and fix them up. Stack Overflow/Exchange is one of the few sites that has the notion that an SO/SE user might have multiple identities, others simply don't. Logging in using a different OpenID is to them as if I was logging in as someone completely different - a new account; migration to a new ID or linking multiple IDs to the same account is not always possible.
I didn't want to be trapped in the position where the authentication provider decides to stop providing that service, essentially orphaning any accounts I created using that ID on other websites. I also didn't want to incur the maintenance burden of running my own authentication service just for me. Delegation allowed me to preserve my apparent identity (my custom URI that serves up a page with links to delegate authentication to another provider), without tying me to that provider. At any point I could swap out Google for another provider, but the URI I'd give to the other websites would remain the same.
The answer provided in the other question basically says to add a Google ID to the Stack Exchange account and be done with it, but that avoids the core issue here. If I change authentication providers to another which does support OpenID 2.0, I have no guarantee they won't drop it at some point down the line. I could find an open source authentication OpenID 2.0 provider and host it locally on the same server that my custom OpenID URI lives on, but I'm worried that will become untenable, if OpenID 2.0 is being killed off because it's not useful/secure. I assume there's a good reason why OpenID 2.0 is being deprecated, and I don't want to be sticking with it when it should be killed.
My question is: is this sort of delegation still possible with OpenID Connect, and if so, how? If it's not possible with OpenID Connect, are there other options that will continue to be supported in the future?