I don't think that it is possible for Manchester united to finish fourth on the table, because it will be hard for them to achieve it. The team faced a lot of difficulties this season, and it is just recently that they have started improving in their performance but it was too late for them to secure a ticket to UCL next season, due to the few matches left, and the big difference in points of the club sitting on the fourth position.
Aston Villa may/may not qualify to the champion league if they are not consistent in their rest matches, because Tottenham is a threat to them, and also have the interest of qualifying to the champions league next season. Manchester united should will be in Europa, I think that fits them better, because they found it very difficult to win their UCL matches this season.
Man United chances are very low of reaching the top four of the standings and finishing there when the season ends. They have a better chance of finishing in the Europa League zone, it is already difficult to overtake Tottenham and Aston Villa, these two clubs have a better chance of getting tickets to the Champions League next season. Although Aston Villa and Tottenham lost points, it is not certain that Man United will be consistent in the remaining matches ahead. Player injury problems are one of the causes of their inconsistency this season, not to mention other internal problems involving players and coaches, which has caused Man United to experience a setback this season.
Personally I don't think Manchester United have any chance of finishing in the top four of the points table. Arsenal, City and Liverpool are sure to be in the top three of the table. Aston Villa, Tottenham and Manchester United are currently fighting for fourth place in the table. But among these three teams, Manchester United is now the most behind. Aston Villa and Tottenham are now in a good enough position to finish in the top four of the table.
It is indeed too late for Man United to realize their ambition of finishing in the top four of the standings. Defeat by Fulham at Old Trafford in week 26, then continuing to be defeated by Man City in week 27, marks Man United chances of reaching the League Champions zone has finished. It's true that the difference in points is still very likely to be reduced, but I haven't seen any signs of a significant improvement in performance within the Ten Hag squad. The victory over Liverpool in the FA Cup cannot be used as a complete reference for Man United next match.
Manchester United team is now 9 points behind Aston Villa. However, Manchester United may have a slim chance of finishing in the top four if United's overall performance remains stable. But Manchester United's performance is still weak and erratic. Manchester United have lost two of their last three matches. Such an erratic performance will not be able to close the gap of 9 points with Aston Villa.