Ederson and De Bruyne appear to be injured, at least that's what the news is circulating. If it is certain that the two players above will not join the team in the match against Arsenal, then it is very possible for Arsenal to get points at the Etihad Stadium. It may be difficult, but the opportunities are there and Arsenal need to maximize their ability to take points.
If Kevin De Bruyne do not play in that game, it will be the second time this season where he misses the game against Arsenal. I do not believe that he will not play though, it is very possible that the coach is manipulating the media to have an advantage. Even if KDB does not play, Manchester City are still very strong, because they already used to play without him as they played some games this season without him being present and were still able to win. The two coaches are not strangers, Manchester City are the top choice to win, Arsenal is not underrated.