I think:
RX 6950 XT is enthusiast-tier;
RX 6900 XT is enthusiast-tier;
RX 6800 XT is high-end;
RX 6800 is upper mid-range;
RX 6750 XT is upper mid-range;
RX 6700 XT is mid-range;
RX 6650 XT is lower mid-range;
RX 6600 XT, RX 6600 and RX 6500 XT are low-end and something has to be entry level.
That ... is just not right. I mean, the xx50 SKUs are minor refreshes of existing models, and
none of them qualify as being a different tier than the model they're based on. I'll even be surprised if they end up being on the market concurrently - they're that similar. And classifying the 6800 as upper midrange is just flat out wrong. You're starting out sensibly at the top, but then your ranking falls off a cliff as you seemingly insist that every SKU is a tier down from the one above.
So, more like this:
69xx: Flagship ("upper high end", marginally faster than the high end)
68xx: High end (2160p >60fps, 1440p high refresh rate)
67xx: Upper midrange/lower high end (2160p60-ish, not quite as high at 1440p)
66xx: Lower midrange - Midrange (1440p >60fps, 1080p high refresh rate)
65xx: Naming-wise low end, performance-wise entry level, price-wise just absurd. (~1080p60)
Now, the range of acceptable/usable GPU performance has broadened massively in later years as higher resolutions and refresh rates have proliferated, and we're seeing far more SKUs than before thanks to that, and especially when mixed with the pricing nonsense going on this all tends to confuse these rough divisions. But your divisions still don't make sense. The 6650 XT is decidedly not going to be a lower midrange SKU, nor is the rest of the 66xx series low-end (or in the same tier as the 6500 XT). Heck,
the base 6600 is pretty much a 1080p120fps GPU (delivering above 60fps at 1440p), with the XT being noticeably faster. Calling that low-end or entry level is nonsensical. If that's the case, where would you position a 1080p60 GPU?
I guess everyone have a preference, but the point is that AMD is marketing the Navi 21 as an enthusiast GPU for 4K gaming. It is similar where you can run a Nvidia RTX 3090 Ti @ 1440p, but that does not change the fact that the company intended the card for 4K gaming.
That's definitely true - higher end cards are marketed for the highest resolutions they can reasonably handle - but high refresh rate is becoming an increasing focus, with 1440p144 or 1440p240 starting to show up in high end GPU comparisons. Those 6800 XT marketing slides
@looniam posted demonstrate this. As there is a wider range of monitors, resoluitions and refresh rates, the framing of products also adapts to this, where even just a few years ago high refresh rate was a tiny niche it's now relatively mainstream - 1080p~144 displays are the new entry level for gaming, after all. GPU makers don't care whether you're buying their flagship for 2160p144 or 1440p240 use as long as you're buying it, after all.