For your info Gyokeres wasn't having any other English premier league club in mind including Manchester United except for Arsenal. He made that clear which was much reason Arsenal had to increase their efforts in signing him to the club. Moreover, Manchester United isn't playing in the champions league next season which I believed may have made Gyokeres prefer Arsenal to United.
Real ones know that there is nothing left in Manchester United, the name has been made but the team isn't really representing the club at any level. Arsenal hasn't miss the Champions League for the last 4 seasons Arteta has been with the club but Manchester United has been inconsistent all this while. Before Manchester United will be in good form, it will take at least 2-3 years before they get theirselves together and how many years is Gyokeres contract to begin with..
For those that have followed Manchester United right from their glory days especially when Alex Ferguson was manager, and seeing the results of their performances currently it is no error that anyone says there's nothing fascinating happening with the club anymore. The opportunity that Arsenal now have in participating in the UCL should be well optimized in winning the league, for the past forum seasons has been their best seasons after many years of not participating in the UCL and with the players they have now in the team they really should stand a high chance of winning the league.