i would have thought this could be worked around.... simply ask the players age and then for ground content block players not old enough to see dead bodies from playing with adults. At that point any content which is inappropriate can either be trimmed down or cut completely.The question is do they do it by getting rid of the dead bodies from Odyssey or upping the PEGI rating of Horizons?
but the bigger concern for me would be that would mean no money at all from horizons players who may otherwise choose to upgrade to oddy. Obviously i do not know how much FD make from game sales, but if all they have to rely on are microtransactions then that would be a very worrying temptation for FD to go full free to play type shinanegans.
obviously this issue hugely goes away if they release a new paid premium DLC (albeit that new content would have to be splintered from the main game)