This England side is a work in progress with some issues, despite the success, and unless they win the whole tournament and everyone involved gets protected status for the rest of their careers, I'd be fairly confident in predicting Trippier won't be starting in the England side by 2020.
He does have a great dead ball delivery, but as is seen often in the league, he's not fast enough or a good enough defender to play in a back 4. This system works because Walker can bail him out every time the ball goes behind and with most teams playing narrow formations he gets completely free license.
However we already know that this England 352 was forced on Southgate by the complete absence of creative central midfielders good enough, he was quite open about that after qualifying when he made the switch. It doesn't suit Sterling and Alli, Lingard and Walker are all out of their best positions. As a result England have actually been pretty shite at creating anything through open play.
So unless the success of this tournament blinds Southgate to the issues with it, he will want to go back to 433 which gets the best out of the best English players if he can. By 2020 the likes of Winks, Maddison, Lewis Cook, Tom Davies, Loftus-Cheek, Maitland-Niles maybe even Foden will be serious options with a few more years of experience behind them, and some of them will be good enough to start.
That'll mean curtains for IMO at least Trippier, and Henderson.
Still he's a nice lad by all accounts and it's good to see him get his moment in the spotlight, although Walker should be getting a lot more praise for facilitating it because without him, Trippier would be the defensive weakness he is for Spurs, where as others have pointed out Sané tore him apart and he fucked up against Juventus too, knocking them out of the CL.
He'll probably get into the Team of the tournament.