Yes, a trademark holder can do that, but the problem is that Rust is supposed to be a foundation, a nonprofit. Even if they legally can, I don't think it's that ethical for a nonprofit to do so.

In case you want a heads-up about a typo in your post: I see the word segway, which is the trademark name of a two-wheeled personal transport device. I believe you meant to use the verb “segue” instead.

I did mean to use the word segue, and no, it was not a pun about trademarks. I will fix it.

My understanding is that they can't. Trademark protections, IIRC, extend only as far as to not confuse people as to the source of some product. If you created a parody to complain, and not to sell a competing product, then fair use would apply. Do you have any examples of when a Trademark holder has been able to prevent a parody?

A nonprofit has as much incentive to aggressively defend branding as a for-profit industry. Deceptive, predatory, and for-profit trading on the branding of a non-profit is just as much of a problem for the non-profit and its mission as the same thing is for a for-profit business.