In many, many cases trans folks change their legal name to their preferred name. A hint so your future concern trolling endeavors can be more successful: your biases become evident when you drag them into it by assuming trans people could never "legally" have the name they want, as if your actual concern with referring to trans people by their desired name is to make sure you use the name on their license. Do you card everyone you meet, or do they instead tell you their name and you use that name? Do you expect anyone to read your comment and believe that if a trans person changed their license to have their desired name, you wouldn't find another excuse to deadname them? Once again, I think you'll find your concern trolling is far more effective when you don't make it so obvious.

In answer to your insincere question, no one demands anything as "a matter of state mandate". C-16 does not even once mention pronouns. If I had to guess, I'd say you're probably building the house of this comment on the shaky foundation of a thousand YouTube videos from the same side of YouTube that you've gone out of your way to watch about C-16. The biggest issue you'll have with that is that it means you're going to have a hard time in discussions with people who are actually even somewhat educated on the topics you're trying to jump into.