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This was a big surprise for me as well. OK, he used a different printer, but the fact that the 3D-printed lens seems optically OK is very impressive.

I have used 3d printed molds to help me create lenses, but the idea of actually printing a lens is pretty gnarly. I think it definitely qualifies as 3d printing - most models require some touchups after printing from consumer printers anyway.

Actually, there are a number of companies making printers that can print high-quality optics. For example LuxExcel: https://www.luxexcel.com/

He is using an SLA based printer, assuming the resin is bubble free, there should be practically no inclusions in the printed objects.