I think you have it backwards, the paradox of tolerance is the idea that we must be intolerant towards the intolerant, rather than showing tolerance freely to even those that wish us harm. It is seemingly a paradox because it says that to spread tolerance we have to actually be intolerant towards a specific group.
The person who made this is either a troll or a fascist, and to me it doesn't really matter which. Poisoning the meanings of words and theories is an old, old fascist trick and that's all that's happening here.
And that "paradox" boils down to the intolerant saw of "you're not tolerant if you're not tolerant of intolerance"
It's a paradox b/c it's not really a paradox, but it seems like one, when couched disingenuously.
But it's like freedom. Can you really believe in freedom if you believe in law and punishment?* But can you truly be free with criminals running amok? So to have freedom, you must restrict freedom of those who would take away your freedom.
A paradox is a seemingly contradictory statement which is actually not a contradiction if you look closely. That's why it's named like this. Being intolerant towards fascists and other intolerant groups is actually a way to promote tolerance, it's a tolerant act.