When the premier resume it's likely that the dynamic of some clubs will change their game probably due to the temporary pause of the league, some clubs that had started improving prior to the World Cup might start to struggle or find it difficult to continue with their fine form likewise those who are not doing well might up their game, club such as Arsenal will have to seek for an alternative to the injured Gabriel Jesus sidelined for three months, he had been crucial to their brilliant performance this season, Man Utd needed to move on after the departure of Ronaldo which I believe won't affect the club likewise other clubs.
This is all still uncertain because we also have to look at other possibilities because of course there are 2 possibilities that will occur whether they will be better, or worse than before.
As for whether Ronaldo's move affects or isn't clear, there will be a difference for Manchester United no matter what happens, but on the other hand, for other clubs, maybe there will be a slight difference if Ronaldo's news about one of the clubs in the EPL blows again, but things like this will be better this is not the case.
I am pretty sure that it wouldn't change much for them, they were trying to play without him before anyway, and they will continue to play without him. They have two good strikers, Rashford and Martial and these are not "enough" players for the time being, but they will have to do, and that means they are going to play as good as they can, Maguire is basically as good as gone too, Varane was injured but if he comes back then Maguire is definitely gone. They are looking at some striker and defender options.
Like for example get both Osimhen and Kim min jae from Napoli together, that would make them one of the elite teams all over again with all other 9 players in tact.