I would guess that their personal reach over the name is pretty limited by a number of factors, including that the town itself has quite a significant similar claim itself. “Oxford Brookes” university, for example, is not a part of Oxford the Ancient University, but it certainly helps their brand to be next door (and as far as I know it’s a perfectly fine institution as far as these things go).
The issue with the Future of Humanity Institute would be almost the other way around: that as long as it’s in-house, the university can hardly dissociate themselves from it.
As far as I know Siskind has never deleted any idea for the contrarianism motivating it getting out of hand. It’s just against his character. Much more likely he considered it revealing his power level (even if he recognised himself as never having really endorsed the idea besides contrarianism in the first place).
Less charitably, more plausibly, at the outside he recognised that it’s a stupid fucking thing to say that makes him look just not smart.