I suspect this would be a very risky proposition for them. The expense would be enormous, so it would either need to be a player with such huge economies of scale to make it work, or it would have to be a collection of businesses that in aggregate could make it economically feasible. I would suspect in most cases, it would be a lot cheaper to just port your software to modern Linux than to try to get react OS over the line. And that's before considering that a lot of the large players will be in contract situations with Microsoft that likely directly prevent this sort of thing