In the game before he was scratched, I will say he was noticeably active / engaged in tying up his man in the defensive zone around the crease below the dots / above the goal line. Not perfect (don't take that as criticism), but pleasantly effective. He has a high velocity shot - clearly near the top of the Sabres roster - but he must be a more complete player to have top-6 impact in the NHL. Many of us will remember Mark Mancari (not comparing them, just pointing out a recent Sabre who had certain primo tools, but an incomplete tool box - and I'm not saying Thompson is an incomplete player; this season will help develop that). I have no issue with scratching him, whether to allow another Sabre some TOI, or to give TT some NHL game looks from the stands.
Agree that Reinhart as the RW1 was more effective, although I favor - at least early in the season - running set pairs and filling in the 3rd forward with "platoon" players, moving them up and down as their individual health/fitness and team health/depth/opponent varies. Thompson should be afforded opportunities up and down that list (along with others).
Hall-Eichel
Staal-Cozens
Eakins-Rieder
Lazar-Sheahan