I personally don't think Manchester United will be the favorite team in the Europa League next season, eventhough Manchester United have a good squad but still, there is no guarantee for Manchester United to get the Europa League trophy. After all,last season also Liverpool became a very favorite team because Liverpool in last season still had a good squad and coach, but in fact Liverpool, AS Roma and also Bayer Leverkusen failed to get the Europa League trophy. Therefore, I believe the Europa League trophy winner is completely unpredictable because every team in the Europa League has the chance to get the best results in the Europa League.
I think Manchester United has good team but it is too early to say they will win Europa League. Last season we saw that Liverpool AS Roma and Bayer Leverkusen had good teams too but they did not win. This shows that anything can happen in Europa League and any team can surprise us. Manchester United has chance to do well, but we'll have to wait and see. The team that can adjust and play their best at the right time will likely win.