Why do you see this as USA only?

Because the announcement doesn’t use UTC to announce the event and there’s absolutely no chance that anyone outside the US knows when some random timezone is, or if daylight savings is active in that timezone or not at the time of the event.

The announcement also tells me that the organisation is run out of the USA, not a place universally known for its inclusivity or global consideration. Reinforced by a text only imagine with no alt text.

I think a tech workers coalition is an interesting and potentially useful idea, but the announcement doesn’t even contain a URL to the organisation.

Which leads to my conclusion, a USA only affair.

I’d be delighted to be wrong, but that’s what the announcement conveyed to me.