https://www.fastmail.com/digitalcitizen/the-future-of-ai-wit...
I wouldn't read too much into it. Unions are just a counterweight to corporate interests in the best case. The places that union bust out in the open are usually the worst offenders, and Fastmail doesn't seem to be that.
I don't have any insider knowledge at Fastmail, but the fact that a labor union could get organized and come into being without any drama from the company probably indicates that the upper levels of the company respect their employees enough to not fight its creation. Seems good, imo
"No, I won't be (coming in on Sunday/'just doing this one extra thing before leaving after hours'/breaking company policy and legal requirements for safety or waste disposal or whatever), please see [section of union agreement], if you'd like to continue this discussion I can bring in my rep and, as required by policy laid out in [other section of union agreement], your boss, and we can all have a chat about this" will get a lot of abusive pricks to tuck tail and STFU in a hurry, with low risk of effective retaliation.