There's no unions for H1B workers. If there's any union stepping up for their interest, it would find mass enrollment tomorrow. Unfortunately, there isn't support by non-h1b engineers, let alone unions.
I am a non-h1b engineer and I declare it is in my best interest to advocate for h1-b engineers. Otherwise management would simply calculate why would they hire me and treat me well when they can hire a more desperate h1b holder and treat them like trash.
Rocking the boat so much as to get fired, fail to find another employer before the visa expires, and be sent back home? A terrifying perspective for many.
Just to clarify that the parent may have edited, but wrote "non-H1B" workers, so they would be speaking about domestic / citizen employees, not ones on visa.