So far Stomp, One For Sorrow are truly rescanned from the film they used. And judging by that Platinum Megamix video It's the way you make me feel & Deeper Shade of blue would be too and we'll have them in 4K.
The rest is just AI Upscaled from really good original master. The problem with Summer of love lies in encoding the upscaled video not because of the source. The video doesn't have enough bitrate to maintain the details hence the breaking.
We can be both grateful and giving constructive comment at the same time. Nobody is dismissing the work they're doing. I am thankful for those HD/4K videos because God knows how many troubles they had to gone through to get them for us. But if I see a problem I will say it because there's a chance they could fix it now or in future uploads.
I'm not sure he's even needed to use AI on most of them, unless he's using something better than Topaz and being very gentle with it, because there's few signs of plastic faces apart from on Summer Of Love. Sometimes a very good SD source from the late 90s onwards doesn't really need anything doing to it.