I will take that bet.
There are already other core utils to choose from. The BSD utils are arguably better than the GNU ones for the use case you mentioned (and permissively licensed obviously). Has anybody “forked” the BSD utils and “taken them proprietary”?
I mean, people can use the code but that does not take away freedom from anybody (at least not in my view).
I am quite happy to go on record and disagree with your prediction. Time will tell.