[uabstraction]

There are plans to support 3rd party identification (such as an E-Mail address or a phone number) and use that as a basis for looking up users across the network, but I don't think it is currently useable. Account migration was brought up recently in the chat room, but it is not defined anywhere in the spec or reference implementations AFAIK. I agree that these are both important features, but I wouldn't worry too much about them unless they are left out of the 1.0 spec.

In the meantime, it's not like you can migrate your Signal, Telegram, iMessage, or even Gmail/Hotmail accounts. I think Matrix needs a few more client/server implementations before the spec can't truly be set in stone.

[Arathorn]

Email identifiers work fine today, actually. They don't solve the problem of migrating accounts, but at least they abstract the discovery process away, as you say.

MSISDN (phone number) identifiers landed on the backend this afternoon; implementation in the Riot clients will be coming very shortly.