Yes - but just because 60% (for example) of the employees can claim some variety of Christian religion and demand Sunday off doesn’t mean anywhere near that many will . For starters, not everyone who can claim some variety of Christian is all that observant and not every variety of Christianity forbids all work on Sundays. I have spent a good part of my life in jobs where people work Sundays ( and Saturdays and nights and evenings) and there have always been plenty of nominally Christian people who were willing to or even preferred working Sunday. In some cases because Sunday got them premium pay , but in other cases because the nature of their job meant they would have either Saturday or Sunday off but not both and they preferred Saturday. I’m not saying it won’t ever be a problem, just that I don’t think it will result in a Hobby Lobby/Chick Fil A sort of world.