I don't like comparing Necas to past situations. Lindholm was rushed and it hurt him, yes, but he clearly wasn't ready. Necas actually looks like he belongs, like he knows what he's doing.
The other thing is, what kind of useful ice time is he going to get in the Czech league? From what I've read it seems like they're reluctant to give younger guys playing time...also what is their conditioning system like? I doubt it's equal to an NHL team's, or even probably most AHL teams. If we're looking at him as somebody who needs to get bigger/stronger keeping him with the Canes would seem to be the best way to make that happen while still giving him some useful minutes.
Of course the best option would be put him in Charlotte but that's probably not even a consideration.