There’s no good way to solve this, though. Returning an arbitrary account can have unpredictable consequences as well if it isn’t the expected one. It’s a compatibility break either way.
Yes there is! Just get rid of it. It's useless. The re-implementation from using one to the other was barely a few moments of work, and even if you want to say "well that's a breaking change" I mean, yeah? Then break it. I would be far less annoyed if a function was just removed and Xcode went "hey this is pointed at nothing, gotta sort that" rather than letting it run in a way that turns the use of authentication functionality into a landmine.
Sure, but not introducing the ability to be logged into multiple accounts isn’t the best choice as well. Arguably, throwing an exception upon multiple logins for the old API is the lesser evil overall.
