They can take away WFH. It’s pretty simple. “You are required in the office.” They will eventually back fill those roles or make those that are left to fill the gap. Either way, they can and will soon.
IMO though full remote is not without serious downsides for the workers as well. Globalized market with localized salaries and alienation being just two of them. Being in my third year of fully remote I can testify to the second one.