I can agree with that. And we have more pushback yet. I could see the "you agree not to sue" clause in 6f attracting some ire.
They're not just idly referring to them though, they're actively using their license. I can see that being too close to tacit approval for WotC. You're always free to release your content without it.
I'm going to be very amused if/when ORC includes a similar clause.