If the definition of undercover journalism is simply lying about ones identity in order to publish secrets with the intent to cause injury to another party, then yes, absolutely, I'm in favor of outlawing it, and a 1 year max seems generous.
Divulging someone's secrets isn't intrinsically unethical. If I reveal the secret that you've murdered someone that's not a secret that you ever had any right to keep.
Likewise these "secrets" aren't something valuable like an algorithm that's in the interest of society to protect. The secret is their monstrous and unethical practices which lower their sales when their prospective consumers learn about them. Keeping it secret doesn't protect competition, it just hides something from consumers that would allow them to make a more informed choice.
Muckraker journalism like this is one of the main reasons the US has regulations for things like food safety and working conditions. Should a journalist go to jail for revealing that a slaughterhouse is hiring 8 year olds, or that there is a mass contamination of a food product that the company still intends to sell? Those can be "secrets" too.
