I think you should look some of this stuff up. Your expectations aren't really in line with the law.
As someone else has posted, once you let a little non-job related material in ("cute doggo pics!!!") you're almost always allowing labor discussions in as well. A strong pro-labor NLRB would (and possibly will) be all over this action.
Right, this is why lawyers are renowned as the fun police. The correct action from the perspective of the interests of the shareholders would be to ban the dog chat and the dad jokes.
Only if management and the shareholders are ignorant and short-sighted. Discouraging union activity with a stick is not a long term win. Maybe with a carrot, or maybe embrace it.
As someone else has posted, once you let a little non-job related material in ("cute doggo pics!!!") you're almost always allowing labor discussions in as well. A strong pro-labor NLRB would (and possibly will) be all over this action.