> do not get my phone number period
I'd also like that, but they apparently use phone numbers as a primary key for account recovery and identification (e.g. on a new device without the old one present), so that's probably very hard to change architecturally.
There are some interesting concepts of "identityless messengers", but this is inherently hard to do on mobile – at least the platform operator will always know which identities are clustered together on a given device if you want efficient push notification delivery over APNs/FCM.
