Oh my god, I think you're right! I'm glad you mentioned it because I totally missed it - I've seen AI assets before but it's normally obvious!
This many-faced blob guy, though he is kinda cute, is proof - check out the different sizes of the eye pixels. That's because it's actually a 512x512 (or whatever) image, which is then downscaled to 32x32 for the actual asset (but for some reason they put the original in the preview).
Personally I'm not that against this, I just wish they'd disclose when they're using AI. I suspect the premium website they're promoting is also full of AI content, which would explain the huge quantity.