Nottingham forest were set to qualify for Champions league but they were not able to perform well towards the end of 2024/25 EPL season. Nottingham forest finished 7th last season and they must be happy that they atleast qualify for UEFA conference league. That's a big achievement for a team that finished just one spot over the relegation zone in 2023/24 season.
United finished 15th last season and as I said if Nottingham forest can make a comeback in next season then any team can do that provided they identify their weaknesses and fix them.
I think that Nottingham was let down by the fact that they were not an experienced team and most importantly, their bench depth was insufficient to withstand such a load until the very end of the championship. Manchester United simply followed Amorama's strategy, and it was to focus on the Europa League, and in the EPL they lost to everyone, so the tables slid into them. They have good potential, I really hope that they will be able to play differently when their main goal is the EPL.