What money does Arizona have to throw at any big named players? Also the way things are going with that franchise, it's more likely that Arizona gets moved elsewhere than Matthews going home.
As for the McDavid coming home vs Matthews going home. One guy is enamoured by the entire city and the largest fanbase in the NHL while having pretty good success playing for a team with competent management and coaching. Unlike McDavid, Matthews has a damn good team around him and great depth where he doesn't have to always be "ON" to give the team a chance to win. McDavid right now is a 2 man team with Draisaitl. If either of those guys gets injured, the Oilers are f***ed. If they both get injured, the Oilers are a lottery team. Leafs without their top 2 players are still a mediocre/ half decent team.
Honestly, it's not even remotely comparable the situations McDavid and Matthews have and will have. Matthews would be stupid to leave the Leafs especially after the money and spotlight he's getting. McDavid would be stupid to stay with the Oilers, especially with the lack of support he's been given.