Ok, I see what you are saying, but I don’t think that there is a loophole here.
The Executive Branch may only take actions that the Constitution allows (same as the Legislative). These are called the Enumerated Powers. Some of them are simple, like requiring the President to give a State of the Union Address. Others are more complex, like allowing the Executive Branch to negotiate treaties. But it then says “The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.” So anything not in the Executive Branch’s enumerated powers is illegal for them to do.
Of course, one of their enumerated powers is to execute any law passed by the Legislature. That is quite open–ended, because Congress can pass any kind of law that they want, right? Well, no. The First Amendment specifically says “Congress shall make no law… abridging the freedom of speech, or of the press.” So we know that there is no law authorizing the the Executive Branch from censoring speech or the press. Thus, the actions of the Biden Administration were illegal. They were explicitly forbidden from taking those actions by the Constitution, and they did it anyway.