Probably because Lassetter had major involvement with Cars Land.
The last two episodes have enough misinformation without trying to erase Lasseter. Disney paid $7 billion for Pixar which at the time was largely seen as really being about getting Lasseter [back] into the company. His role was expanded after the acquisition including what was supposed to be a ceremonial title at Walt Disney Imagineering. He is the one who pushed to change Car Land to Cars Land and then ensured that it was protected when the Disney’s California Adventure project inevitably went over budget and had to be brought in back in line. His role was very much downplayed.
I've also heard there's a whole cultural thing in mainland China of being negatively viewed if you back down/skip something in public (hope I'm making sense). For example if you make to through the line of SM (in Shanghai if it were built), realize it's a coaster at the last moment, back down and exit, you may be heckled, etc. I'm not sure if this is true or not but this would also make some sense.
