There is a big difference between that and what is being discussed in this article though. Unions are dealing with pay and conditions - important, but ultimately just aggregating topics that employers and employees were going to negotiate around anyway.
This article is talking about:
* Amazon workers are demanding more action from the company on battling climate change
* Microsoft, employees say they don’t want to build technology for warfare
* Salesforce, a group has lobbied management to end its work with the U.S. Customs and Border Protection agency
* Google, [employees] want a say in and control over the products they build
Those are issues going way beyond what an employee can reasonably expect to influence. Being employed by a tech company is an achievement, but the end of the day tech workers aren't that special. They don't formally get to decide how the world works.
They absolutely can't take to social media to complain about these issues and expect to hold a job with the company they are complaining about. This type of activity isn't acceptable; they can't draw a wage and overrule strategic directions from people with capital at stake. The options are work or walk.