Yes indeed, after all Haaland is a great player which of course will make Haaland more closely guarded by opposing defenders. Therefore, it will make opposing defenders prioritize stopping Haaland's movements. So yes, from this style of play, then of course teamwork is very much needed and other Norwegian players cannot always depend solely on Haaland's skills and abilities. Also, with this result it seems that it will still be difficult for Norway to qualify, because so far Norway has only gotten four points from the four matches that have been played.
Being dependent on a single player doesn't always work well. And we have seen this in the case of teams like Portugal, Belgium and even for smaller teams like North Macedonia and Wales. But then, Norway is a very small country and the national league (Eliteserien) is not very popular. Recent downturn in their performance can be attributed to the overall decline due to smaller player pool. Norway is a country that is rapidly ageing, much like Danmark, Germany and Italy. And unlike France and England, they don't have a large migrant population who can inject fresh blood to the national team.
They used to be a bit better but they were never a team that had any chance to win euro cup to be fair. When was the last time you saw Norway as the top three team to win any euro or world cup ever? I do not remember that happening anytime in the past, maybe it has happened back before I was alive, that is a possibility but I do not think that they were ever that great. So, with Haaland now on the field, they are still not that great and can't really make that much difference.
I would guess they will win "some" games, but they are not going to win it all, I do not see even a semi-finals for them neither, the very best ever they could hope for is a good draw against weaker teams hopefully, otherwise maybe not even qualify for it as well.