My take...
Not a chance does Tiedemann make this team out of spring training. He's pitched 11 innings in AA, he's not going to be 21 until August, and he's not on the 40 man roster. You'd have to dump someone to make room for him. It would be poor roster/asset management.
And in case you're going to cite Manoah....Alek was 23 when he got called up after his 18 innings in AAA. No need to rush Tiedemann. The team has depth on the mound. Should they run into serious injury issues, poor performance issues, AND Tiedemann sets the world on fire, maybe at that point do they look at that move...but after the All-Star break would be the earliest I can see that happening...and that's in a perfect world.