For Maguire a change of the location, or the league to be more specific, would be the best way to move on for him. I think that his career is more or less over in the Premier League because it is the same people in the end who are watching him and who are giving him the bird if they see him making any mistakes. Minor mistakes will already be an issue because he has no room for error left, which is bad for a defender as the press will attack him as soon as he makes a small mistake.
Of course Maguire has to see the opportunities that exist because it is very difficult for him to develop his qualities in the Premier League so he needs an easier League for his career. Apart from that the interest from the top teams in Serie A in him opened up opportunities for Manchester United to release him in this summer's transfer window. For the value of the release maybe Manchester United can adjust well so that the Serie A teams can reach it because we know the Serie A team finances have not been very good in the last few seasons.
The time for the transfer market is still long. I think some teams are still actively trying to sell players or buy players in this summer transfer window. Manchester United are still trying hard to convince Atalanta to agree to their offer to sign Hojlund in this transfer window.