A metaphor: I once played in a D&D campaign where a player tried to create an extremely overpowered but technically legal character. His justification was that he would only use the extreme powers in moderation, so it would not be unfair or unbalanced. But why would he ask for such unprecedented powers if he didn't intend to use them?
I actually did that for a campaign. It wasn't extremely overpowered but I did have some abilities that could have been extremely OP if abused. I don't even think it was really legal as far as RAW was concerned. In the end I was probably one of the least effective characters, but I was able to do some cool things with those powers and we had fun roleplaying it.
The threat already silences the opposition. You don't have to use it to silence people.
I understand the metaphor, but there is a huge difference between a D&D player and an entity such as a government.
For starters the government is not in the habit of releasing these new powers, once it's established it will stay for a very, very long time.
And you can be sure the new powers will be used in unintended ways, which the citizens will have a hard time blocking.
So it's actually very simple: No to Chatcontrol, now and forever.
Another one: someone buys a sports car and promises to drive within legal speed limits at all times.
I actually think that a role playing game is exactly the soft of situation where this is in fact reasonable.
There is a lot of mythology about gods walking among men, hiding their true nature, etc. And more recent examples include the TV show Lucifer.
Someone wanting to roleplay that sort of being is entirely plausible. Without knowing the person's personality (which you presumably did) it's hard to say whether they would have genuinely wanted to do that or if it was an excuse.