I hope not. Publishers know that it's impossible to typeset an ePub exactly as you want it displayed since display is under the control of the reader, or the reading device. At least until pdf is no longer synonymous with letter paper/A4, ePub is a flawed format.
And for the umpteenth time, the pdf format is size agnostic.
How is that different from the old default, which was MOBI?
Does Amazon still strip metadata and cover art from user-provided epubs? If they're still intentionally gimping the implementation, IMO it's a step backwards
Not sure about metadata, but cover art persists through the email-to-kindle process at least.
It does on first web sync after the ebook is transferred. It can be fixed (by transferring again) and then it won’t be removed on subsequent sync.
At least author title and cover is kept - I’ve sent few books few days ago. There was a period when it didn’t handle them well when sent via email, but they fixed it few months ago