I bet that Haaland not only will continue to score goals like that, but he will also score a lot more. The main reason is that everyone is tightly marking Haaland now, which results with him not being able to score that easily, but if he can't score easily, then how could he score more?
The main reason is that after first few weeks, like maximum of 10 but probably less, teams will realize that Haaland is not their only scorer, and City is using him as bait, you fear him scoring, so others score easier. Then teams will end up defending normally, and that will make Haaland score a lot easier as well. That's how I think the season will go, first 2 months not that great, after that it is all goals galore for him until the end.
Interesting theory (I don't believe in it) but with City having at least a couple of very weak teams in the group stage, Haaland could try to score a record number of Champions League goals. The bar set by Ronaldo is very high, but so is City's degree of dominance. Therefore, if he manages to make a hat-trick a couple of times in the group stage, then everything is possible.