It's a great question, other forum users have been told that the contract with Peacock changed. So they are probably in the process of clearing out duplicated content.
As for content like Bates Motel, it's on All4.
My guess is that it will be used for Peacock originals, like Bel-Air. Although if they were serious it would be the home of NBC distributed content like Chicago One, Law & Order, Young Rock etc.
The Now advisor explained to me that some Peacock content such as Bel-Air and Vampire Academy is remaining and that other content is available on Hayu (which I note you have to pay a separate subscription for). Sorry, I wasn't in a position to be able to do this the other day, but it seems prudent to make a new topic with all of the information that I obtained from the Now advisor, so that it can be easily found/referenced to.
So here are the full lists of removed content and content still available on Hayu in this dedicated topic: https://community.nowtv.com/t5/Content-Issues-Missing-Episodes/Complete-list-of-removed-Peacock-cont...