This is demonstrably not true.
He has fairly equal representation as the other founders on their history page
https://www.pixar.com/our-story
He also is directly mentioned in the Disney+ docuseries on ILM, and was part of Catmul’s retrospective on Toy Story as recently as this year
https://youtu.be/q1Uq8b2ooVk?si=zjHSHjGHtymH-kKy
Pixar and Disney haven’t been shying away from his involvement in their history
Hm, the fact that he was mentioned or referenced does not prove that his role was downplayed, a quick search of the interwebs shows:
- 2018 Oscars: Despite his massive influence on Coco, none of the filmmakers mentioned him by name in their acceptance speeches for Best Animated Feature.
- Film Premieres: Lasseter did not attend the 2018 premiere of Incredibles 2, a film he was heavily involved in, further signaling his detachment from official company events.