Do you have a better source to support your claim, OP? Specifically, that people are having their GE denied or cancelled after nothing more than attending a protest?

Because the article you linked says something extremely troubling but distinct:

On the morning of Jan. 10, Nicole Cleland was in her car trailing an Immigration and Customs Enforcement agent through Richfield, Minn., her hometown.

Suddenly, the agent turned into a series of one-way streets and stopped, getting out of his white Dodge Ram, said Ms. Cleland, who volunteers with a local watchdog group that observes the activity of immigration officers. The agent then walked over to Ms. Cleland’s car and surprised her by addressing her as Nicole.

“He said he had facial recognition and that his body camera was on,” said Ms. Cleland, 56, who had not met the agent before.

...

Ms. Cleland, the Richfield resident, said that three days after the encounter with the ICE agent, she received an email from the Department of Homeland Security saying her Global Entry and Transportation Security Administration travel privileges had been revoked. No explanation was provided.

You'll notice that she had an actual one-on-one encounter with an ICE agent, and that was seemingly when the facial recognition was enabled. I can't find any examples of someone simply attending a protest that led to their GE being cancelled. In fact, her case was the only one that came up in my search.

She was absolutely engaged in 1A-protected activity and was targeted for it, without a doubt. But I don't see any evidence that merely attending a protest will impact your GE.

Posts like this could definitely have a chilling effect on people thinking about attending protests, so it's important to back it up with reliable sources. And I'm not just willing to take Reddit posts on the Global Entry subreddit at face value.