If anything, this moves it towards anyone having more access to everything. For example, reject isn't going to be treated anymore as a bounce. Now, provider policies still can and would be BS, but the standard doesn't tell them to do it certain way.

> by the big three

Which big three?

Gmail has something like 1.8 billion users. iCloud mail around 1 billion.

Microsoft with 400 million users of its email is closer to Yahoo! Mail (225 million users) than to the big two.