Yes, I also thought that prediction was funny. The most expensive club in the world will perform well next season - who would have thought 
I think Haaland will break goalscoring records in at least the Premier League, he is a very effective striker and City's midfield will provide him with many chances. Well, it's pretty fair - in the national team he is deprived of such opportunities, but at the club level he will have a chance to show his maximum.
Manchester City perform well in Premier League in recent seasons, without Haaland. They need Haaland to win Champions League, not Premier League. They already dominate Premier League and Liverpool can not beat Manchester City in many seasons. I think Haaland will break goalscoring records in at least the Premier League, he is a very effective striker and City's midfield will provide him with many chances. Well, it's pretty fair - in the national team he is deprived of such opportunities, but at the club level he will have a chance to show his maximum.I think Haaland in theory is very good to play in Premier League and with the whole attacking system of Manchester City, Haaland will receive many good key passes from his mates. The rest part is finishing such passes and converting them to goals. I do not doubt that Haaland will fail to convert chances to goals.
City could have lost last season - do you remember what the situation was with the score 0-2 for it? Liverpool had real chances, but everything turned out the way it did. So in order to maintain an advantage, City must continue to improve and the purchase of Haaland is valuable in itself without the Champions League. By the way, the results are very random there, so no player or group of players can guarantee the UCL title.