Pretty cool to see strong numbers by both... Best thing for hardware from either party being better or better value is healthy sustained competition.
Anecdotally, I've heard a few people either explained to in-store or told me directly that they thought the Pro was designed for 4K TVs, but in so far as that you'd only buy a Pro if you had a 4K TV. Or, at the very least, it was unclear enough that they didn't seem interested in a Pro.
Pro is a pretty great name, and I think their advertising has been OK, too, IMO (for what it's worth, I've studied/researched consumer behaviour academically for 3 years after I formally graduated; I'm no expert or professional, but at least in theory they've hit a lot of the right notes), so I don't think it's on Sony's marketing. I think part of it is purely that 'any' upgrade unit is always going to face some level of consumer confusion, especially when the name is related to, say, performance or features rather than just its physical design (e.g. slim). Wii U had the same problem; I'm sure the Scorpio will. So when there's uncertainty about a product, and therefore uncertain demand for it (there's much more clear consumer demand for, say, a PS5 or a iPhone 8 than changing your PS4 to a Pro or adding 4GB RAM to your PC because it's at the margins rather than generational) I think a lag like this is somewhat natural. Always going to be just the sophisticated consumers that early adopt as long as it's an optional 'upgrade' (and not at release, so genuinely an upgrade, unlike a iPhone 7 or 7+) rather than a generational 'replacement'.
The good thing is it should indicate more sustained sales throughout the year as more consumers consider upgrading, and it should be good for the Scorpio, too, because it better solidifies mid-generation marginal upgrades within consumers as a product, so it should cut down on the sort of pre-purchase process since basically slightly more folks will know 'oh, it's like a Xbox Pro I understand that I want that.'