John Cominsky being placed on Regular Season (Short Term) IR was expected and inevitable, once he was on the Lions initial 53 (techically,52) man roster.
I expect Kyle Peko to be signed to the Lions 53 roster. What's more uncertain is whether it will be before or after the regular season opener vs. the LA Rams on SNF? If it's after, then Peko's base salary for the entire season isn't guaranteed. Either way, I anticipate Peko will be active for the Rams game for the Lions. If he's still on the PS, I believe he will be elevated from the PS for the game.