Assuming not-Montana US, you can be fired for any reason other than membership in a protected class (race, religion, etc). Attending an ice cream social, even a company one, is not a protected class.
I’ve heard of similar things. Boss wants to see who is the least busy, so they do something like open an employee gym. Then anyone who uses it is fired, because “if you have time to use the gym, you’re not working hard enough.”
Exactly. There was also a puzzle table once. The higher boss said he loved to see people building teamwork and closer relationships and liked the puzzle. I luckily knew the whole time that even though he said this he fucking hated the puzzle. I winced everytime he'd catch someone working on it. Some people are just oblivious AF. "He said he likes the puzzle!" Yeah he said that, but he absolutely does not and you're probably on the shit list now