I was having a chat about this with a UX guy. His argument for using a similar flow was that the username/email will have to be validated at the point of registration anyway so you might as well make it easier for the user when the email is wrong. I couldn't really refute this logic.

If you throttle both login and registration, then surely the risk is minimised while keeping the user happy?

[–] LeapSecond@lemmy.zip 13 points 2 days ago

You see the registration problem in so many places. If the username is an email, the proper way to validate it without revealing if an account exists is to accept any email address and if it already exists say that in the registration email you would send anyway. With the appropriate throttling if needed.