I think 'willing' and 'able' are 2 different things.
I think that TY et al have been rather duplicitous, myself. Of course no one would be likely to go to that much trouble if their own DCs couldn't be guaranteed to benefit. I have just a hunch that he knew bleddy well when he set up his FS that 'the rules' would be quietly changed once the hooha had died down a bit.
We will see absolutely the same thing happening with the NHS if this government get its way. The private 'willing providers' will, on paper appear to have to abide by the same rules as the NHS providers- but the devil will be in the detail (Item 2, subsection 24 of a school's Proposed Admissions Document, anyone?). The private providers know they will fail to make handsome profits if, like the NHS, they are forced to treat all-comers, because those pesky old, ill people with chronic conditions will keep coming. So they will be quietly allowed to 'opt out' of the non-profitable stuff- the government will have to facilitate this or otherwise, no private providers will step forward and the NHS privatisation will fail.
In the same way, the rules will have to be quietly changed re FS admissions to ensure that privatisation of state education by stealth can continue.
FWIW if someone set up a FS which wasn't complete loons-ville near me, one which found ways of selecting by middle-class'ed-ness, enforced parental involvement, 'exclusion' of disruptive DCs, a rigorous (but to my liking!) curriculum and free- I'd be first at the door, MC sharp elbows flailing, eager to advantage my DC over the hoi-polloi.... but I don't think I should be allowed to do that, certainly not using everyone else's tax paying ££ to advantage my DC over theirs.