While the Wings can dictate PP time in GR they aren't going to dictate 20+ minutes or things like that as it is unheard of. He will be punished for mistakes and come the third period they are going to play to win.
I don't think anyone's looking for Seider to get ridiculous ice time in GR. Prospects don't need ridiculous ice time to develop, they need to play in all situations PP, PK, O and D zone starts. I wouldn't want him to get much more than 20 min a game in AHL, and I don't want him in DEL getting 12 either. It's not good to overload prospects with too much ice time, so I don't know where your points are coming from.
It's OBVIOUSLY a blend of both. You can't just blatantly not play prospects. But if you don't think a guy who wins a Calder Cup is going to sniff NHL jobs, I think you're dead wrong.
Look at our AHL roster. Do you see how many veteran level guys there are? Do you realize how big of a role a lot of those guys play? There is a reason for this. You could construct our roster with mostly prospects, but teams don't do that. Saarijarvi has been buried under AHL vets most of his career so far. Turgeon has been buried under AHL vets most of his career so far.
Unless we make roster moves, even despite drafting Seider at #6, I am expecting vets like Lashoff/McIlrath to have a bigger role to start the year. Guess we will have to see what Yzerman does to address the log jam.
Oddly enough, the vets you mentioned are actually on Wings contract, not GR. If the Wings wanted to, they could assign McIlrath or Lashoff to the ECH or put them on the NHL roster. (Not that they would do either...) McCrea (1 yr), Crawford (2 yr end this season), and D'Astous (2 yr) have contracts with GR.
On offense, the GR vets are Ford and Shine. Plus GR signed a bunch of kids out of juniors.