Some might be surprised by this, but for me (if I were a GM) a blue-chip" prospect is a guy I am 100% sure will have a lengthy NHL career in one role or another (read at least a few hundred games). A team is far more than just it's stars and while it's much easier to buy yourself the supporting cast instead of the stars, the good teams still develop both themself because it's the cheapest.
So no matter wether the guy will be a 1st line star or a 3rd liner, if I am sure he will be in the NHL and help my team win game in game out, he is a blue chipper for me.
For my Lightning that would be the following guys:
-Andrei Vasilevskiy
-Adam Erne (he could develop into anything from top line power forward to 3rd line checking guy, be he will make it)
-Slater Koekkoek
-Nikita Nesterov (granted he is more or less a fulltimer now, but he is here to stay for a long time)
Guys like DeAngelo or Brayden Point might have more upside, but there is still far to much bust potential IMO.