“We have great respect for the ESA as an organization, but we do not feel the vision of E3 2020 is the right venue for what we are focused on this year,” a spokesperson told GamesIndustry.biz."
So rumor has it Sony and ESA are not getting along. Whatever Sony wanted to do was not in line with what the ESA wanted.
Iirc there were E3 2020 leaks that the ESA is planning to turn E3 to more of a fan event like Gamescom. Sony might have disagreed with that.