I don't know if it even works that way. Lucasarts no longer holds the rights to Sam and Max. I expect this means that legally, they don't even have the right to sell their work involving these characters to a 3rd party, even if this 3rd party is the rightful owner. Steve Purcell would doubtless be required if such a transaction were to be made.
But this is then further complicated by the fact that the game was developed in an engine proprietary to LucasArts. Even if Telltale Games had the rights to the game itself, they don't have the rights to the engine used to make it (I don't know if it was made with SCUMM or not), and I wouldn't expect Lucasarts to part with that.
And trying to remake it in the telltale engine would probably be like starting over from scratch.