"Stock Android" usually means "what runs on Pixels" in Android user circles, not actually AOSP. It's a comparison between Samsung/Huawei/Xiaomi/... and Google/OnePlus/Motorola/...
“Stock Android” means where Google does inside it what I have listed above in less savoury words. The ones you’ve listed are basically compromised devices in your pockets — so a notch higher or lower, depending upon how you look at all this :)