Don't confuse a trademark with a patent. Even if Google uses "go links" internally, the fact remains that the trademark is registered and in use by another entity.
Trademark was found via a Hackernews thread? You guys are good :) We have three trademarks that we've defended successfully before. Would encourage anyone wanting to try to use go/links, to just sign up to https://www.golinks.io ... it's completely free to use, forever and you can get started in a few seconds. We're trying to get go/links everywhere and are happy to be at the forefront of that :)
I was going to say the terminology comes from inside Google, where afaik go links were invented. However, yeah, that's straight up a trademark. You'd need a lawyer to know whether the trademark would survive litigation, and whether the s on those trademarks makes a material difference. (OP isn't plural, those trademarks are)
A trademark is not a patent, you don't need to prove you were first to have "the idea". [IANAL] It's the first to use the term in a commercial context, which Google has not.