He will get an ELC but I believe he'd have to play in an NHL game to burn a year of it. I also don't think that would be of importance to him, goalies development takes so long that the expectation of being in the NHL before his elc expires would be lofty at best.
I think he'd need to sign a PTO like tuch did to play with laval. If he signed the ELC to play with the habs, he wouldn't be allowed down.