As Cyril pointed out at the beginning; "'Je suis Charlie"' is a slogan adopted by supporters of freedom of speech and freedom of the press..."
être Charlie = support freedom of speech and freedom of the press
By extension, "ne pas être très charlie" would mean someone is NOT a strong supporter of freedom of speech and freedom of the press.
The strongest connection I can see between Jérôme Salomon and this reference to free press would be his "volte-face sur le port du masque" in France and the inquiry into why there was a change in the information given to the public during lockdown.
https://www.lexpress.fr/actualite/societe/masques-nous-avons... "Did you know Salomon was not a strong supporter of freedom of the press?"
It also might just be gobbledy-gook nonsense created by a chat-bot.