I think it's a misspeak to say that "it would be strange if Manchester City did not get a ticket to the Champions League next season," nothing is strange here, we all expect the worst for the club this season and it doesn't just happen, it has started since the beginning of this season. Perhaps you are viewing it from the past glory, but you shouldn't, time moves fast and we should judge situations by the current. Not even for what Man City played with Brighton in their last match, they are still weak and have only managed to win just 2 matches in the last league games. Man City should even pray that Brighton or Newcastle should not displace it, it's not only Chelsea that is the problem.
Manchester City are in a weakest mode since 2017 - 2018 season but they still have enough star players and experience to finish this season in top four. Fortunately for them that Premier League with good performances of representatives from Champions League, Europa League to Conference League, will very likely be given five slots for next season in Champions League.
This means, the target of Manchester City can be top four or a fourth position but it can be a little bit easier with a fifth position. If it is a fifth position, I think they are very likely able to get it but to be safely they will aim at a fourth position. Brighton is making surprise but let's say they won't be able to represent Premier League well in Champions League.