I think it is fairly obvious that the “inventor” of the paradox of tolerance didn’t use the term with the meaning that it is self-contradicting and therefore wrong but rather the alternative definition of “a statement that is seemingly contradictory or opposed to common sense and yet is perhaps true”. And the peace treaty/social contract solution is assuming that you can’t be tolerant to the intolerant, so they agree on “yet is perhaps true” part. And the first section is obviously true.
To be fair there is more than 1 definition.
I think it is fairly obvious that the “inventor” of the paradox of tolerance didn’t use the term with the meaning that it is self-contradicting and therefore wrong but rather the alternative definition of “a statement that is seemingly contradictory or opposed to common sense and yet is perhaps true”. And the peace treaty/social contract solution is assuming that you can’t be tolerant to the intolerant, so they agree on “yet is perhaps true” part. And the first section is obviously true.