You could still play Faery/Sage and cast every spell other than MS. MS is not the only spell in the game, but it is very powerful and personally I see why it should only be given to dedicated Mages (who are playing Mystic at the exclusion of attacking/thief abilities.)
Last age player choice was limited by the fact that Faeries already had MS, so there was no reason for anyone to play a Faery/Mystic. On the contrary, this causes Faeries to actually make a choice, it doesn't take away choice.