News flash- the vast majority of Church-goes attend church on Sunday- and that's why the default would be Sunday.
Not saying I support this exactly... but the idea that this has something to do with the Pope is a stretch. Most 'Christians' in America are evangelical/protestant, and reject Catholicism and the Pope... and even some leaders in the catholic church reject the pope.
MOREOVER, what these project 2025 guys are proposing makes provision for people to change their rest-day from the default sunday to another day... so I don't see the problem. These commentators try to make it sound like saturday was the only other option: but that's not what the text says at all- saturday was merely the example.
I don't know who these people are; but, they look like low-key liberal shills. I am red-blooded MAGA; and even from where I stand, this agenda 2025 is anything but a "slam dunk". The things in agenda 2025 cannot be accomplished by the executive branch alone. They should probably call it "agenda 2040".