The core of their team wasn't competing with the Rams. I think moving him now when they can use the value they get back in trade to speed the rebuild is wise. It was time.
So right decision IMO but the other decisions around him have been poor. Bringing Pete back for starters. Generally if you're gonna move the QB and reload then cycling the coach is the way to go to start that timer with someone you want to move forward with. Pete has a long tenure already. Should have fired him and the GM, but at the least the head coach should have moved on.
Keeping him tells me the plan should be to make that defense dominant. Also Metcalf is not going to work well with a rebuild, and probably won't be patient as the young QB comes up to speed. So if this isn't a precursor move for Watson I think they would have been wise to sell on Metcalf while he's still got enormous value. Before he shows the ugliness of his personality in the losing ahead.
But I give them some credit for trying to reload. It's better than sitting back and trying to squeeze a few more playoff runs with quick exits out of the oompa-loompa.