He had a fantastic relationship with Amorim when he was manager at Sporting Lisbon therefore I have found his overt desire to join Arsenal somewhat strange. It seems as though Amorim did not try to buy him after he made it clear he was interested in moving to Arsenal.
He is a player that has enough talent to be playing in the Premier League therefore I hope he joins Arsenal or any other big team.
Manchester United was also interested in signing him actually. But as far as I know he rejected them despite Amorim's presence there. Maybe the Champions League participation also affected his decision seriously.
I hate the fact he might end up at Arsenal because that's going to give them a good boost for the title challenge. Gyökeres has given sporting all his best and the way they're returning the gesture isn't nice. He isn't being treated like a player that have given the club his best years. They should just allow everything to go smoothly and stop being greedy. Gyökeres is 27, still has about 3/5 years of talent left in him and during this years, I think Arsenal should get a good chance at winning the title if other teams don't strengthen their squad.
I agree that Gyökeres can really be the key player for Arsenal to finally start winning bigger championships. They can even go for a Champions League trophy with a goal machine like him.

But it depends on whether he maintains this performance. Because he is going to play in a much more different environment.