I agree with your reasoning there, it was a home game for Arsenal but in fact it wasn't just about De Bruyne. Pep Guardiola has difficulty making his squad appear impressive because Arsenal really has an effective strategy. Arsenal built a lot of attacks, they appeared to press and created more goal chances than Manchester City and in the end Gabriel Martinelli's 1 goal was enough to secure 3 points for Arsenal even though it came a few minutes before the end of the match.
A really mature scheme must be thought of now for Arteta and Pep because apart from the whole team there are several core players from each club who really need to anticipate their movements so as not to be troublesome.
KDB, Doku, Foden and Haaland could be very troublesome in terms of movement especially when their movement without the ball is not marked by several defenders which could be troublesome for Arsenal but on the other hand for Arsenal players it is also the same where Manchester City must try to keep an eye on the movement of Arsenal's flanks which are indeed quite fast where Martineli and Saka are possible to comb the field not to mention some midfielders who are always active in attacking like Odegaard it could backfire if released just like that.
With a strong atmosphere now of course we expect an interesting match in this case because after all it is important to make the competition even more worth seeing especially the results of this match could be decisive for the final result of the season.