About Giovanni Pico della Mirandola

On his wikipedia page, it states that "Pico believed in universal reconciliation, as one of his 900 theses was "A mortal sin of finite duration is not deserving of eternal but only of temporal punishment;" it was among the theses pronounced heretical by Pope Innocent VIII in his bull of 4 August 1487."

①It seems to me that this is the first explicit condemnation of universalism as such in the history of the Church. Is there any incident prior to this
that could be so considered?

②Are there any leads as to how Pico arrived at his belief in universal reconciliation?
There seems to be a large gap of explicit universalists before him.