No, it was designed to shield law enforcement officers violating the Ku Klux Klan Act from legitimate lawsuits. See [1], which is the case where it started. Qualified immunity is only relevant when the lawsuit is not frivolous anyway...
If you look at the significance of the place (The Tian'anmen is literally on the national emblem of China, and the tomb of Mao is on the square for example), it's hard to rename something that widely known. It's much easier to pull one of the events that happen there under the rug, because unlike in the west the name is associated to much more.
Specifically, it violates freedom 3 of the FSF definition (redistribute changes), and section 3 of the OSI definition (Derived Works). This freedom is at the core of what FOSS is.
And that's before the violation of freedom 0, "The freedom to run the program as you wish, for any purpose" of the non commercial licenses.
I'd personally agree with that (hence my quotes around the having become part), although I'm not nearly caught up with the lore enough to know whether equating open source with the FSF and OSI is fair. Also can't vouch for the thread starter's opinion of course.
I don't think this commit has anything to do with wireguard. It's a fix of a bug in the kernel TCP stack, which wireguard doesn't use. (Beware, the wireguard-linux repo is a "fork" of the complete linux kernel)
And even if it did, a userland TUN implementation of the wireguard protocol probably doesn't have the same bugs as the linux kernel one.
Looking at the supported platforms, it looks like the only one is Linux. The README has this to say about it though: "This will run on Linux; however YOU SHOULD NOT RUN THIS ON LINUX. Instead use the kernel module; see the installation page for instructions."
The bill authorize it using any technical means, specifically mentioning using classified methods («prescrire le recours au moyens de l'État soumis au secret de la défense nationale»)