He's doing brilliantly but this is massive hyperbole in my opinion.
He's 22 and can't even get in the England Under 21 squad. Joe Bursik is the same age and has 10 England under 21 appearances, more experience in the Championship and now he's signed for a team in the Champions League. Pickford was making his full debut at 23. Aaron Ramsdale is only 2 years older and has 150 premier league appearances and played European football. At the same age Dean Henderson was in a Sheff Utd side which got promoted and conceded the fewest goals in the league. He followed it up with a good season in the Premier League.
Patterson can be an excellent goalkeeper without ever really being in the international conversation, which is probably beyond him, unless he continues to improve far in excess of what someone normally would at this stage.
For him to develop into that level of keeper though, he needs to be in the Premier League next season. He's not playing for his country in the Championship at Sunderland.