I see no reason to bargain for "limited number of fans" being able to attend the final, couple of thousand coming to the game in a giant stadium won't bring back any atmosphere either way.
It should be simply because fans can't travel to Turkey. And guess what? Cases in Portugal are on the rise and by Monday they might also be on the red list as well. But UEFA in their infinite wisdom decided to move it to Porto.
Just basic common sense to have it at Wembley. It's not like either team has an advantage, and at least there will be some atmosphere. A CL final in front of 200 people will be absolutely pathetic.