From a statement to the markets by Frontier made not that long before the fold-down of Horizons in to the base game only about half of base game copies sold had a corresponding copy of Horizons. Given that the fold-down took place nearly five years after Horizons launched, and that base game players shared content, including CGs, with Horizons players throughout, I expect that Horizons players, on whichever platform, will continue to share relevant content with Odyssey players going forward in the same manner.
It's not really a platform issue, more a game version issue - and, if previous uptake of a paid DLC for the game is anything to go by, the majority of PC players don't own a copy of Odyssey - and they also expect to be able to continue to play the game.