Thanks for the link to photos and sound test. Glad they haven’t thrown out the best feature of Cherry blacks: sound. It’s hard to tell what changed but my guess is the change is mostly in the housing instead of the stem. It appears they reduced the gap between stem rail top surface and housing.
Based on my polishing experiments, top stem rail top surface was not always in contact with housing, at least not as much as stem rail sides and edges. Top part of stem leg sides also seem to be more in contact with housing now. Assuming this is what they meant by increasing the surface area, I think the benefit is not in the sound but in the feel of the switch, making it feel tighter and more solid.
I am going to get a batch to polish. Maybe they don’t need polishing at all which is best for everyone.
UPDATE: Looks like that UK store is the only one selling them. Going to wait til they’re more generally available. It’d be great if NovelKeys can make them available in the US at a more reasonable price.