Sure, but because a specific rule is in play, this example fails to demonstrate that the DM has the ability to deny a character’s action in the general case. The Paralyzed condition expressly says that a character affected by it can’t take actions on its turn*. Can you cite a specific rule that says the player can’t take certain actions when relevant background knowledge hasn’t been established?
*well, technically it says the character affected by it is incapacitated, and the incapacitated condition says the character can’t take actions on its turn, but tomato tomahto.