> But let's say this is just legalese. Does it seem wise to let your core product be sold under contractual terms defined by your direct business competitor, which by their own admission has no interest in "funding the competition"? (they've been quoted saying this).

I think it's probably fine. Like, if WotC is willing to sell their product on these terms, it's probably safe for me to sell my product on the same terms, especially if we're direct competitors. Obviously there's a risk, but there's a risk in not competing too. Compare price matching.