We just wrote one that does something similar for Typescript if anyone wants us to OSS it... The idea is that any stale code causes a HUGE amount of headache and removing it can be a life safer.
To be fair, I am a native english speaker and this is the first time I've seen it used as a verb. "OSS" generally acts as a noun. In this instance I would have used "open source" as the verb of what you could do to your proprietary Software, after which it would become OSS.
Other commenters saying it isn't used as a verb are wrong. They're correct that people never say "I open-source softwared my last project."
However you can definitely use "open-source" as a verb: "I open-sourced my last project." It's pretty common. And in this case "OSS" stands for "open-source", not "open-source software".
What's confusing you is that when we use the abbreviation "OSS" we're really intended people to read that as "open-source" even though the abbreviation technically means "open-source software". btw, you would never verbally spell out "OSS"—chiefly because it's the same number of syllables as "open-source".
I wouldn’t add that to your list of widely understood verbs based on a single HN comment. Any noun can be (mis)used as a verb in modern English, if speaking very informally, and often with a slight tongue-in-cheek humour about the clunky incorrectness of it. Some examples eventually become mainstream (to google something, to text someone, to roadmap it).