Of course they do. There always used to be sequencing in the models... For example and this is just "high" end going back as far as I can remember...
3850, 4850, 5850, 6850, 7850
3870, 4870, 5870, 6870, 7870
Then they changed it....
270/x, 370/x, rx470, rx570
Radeon RX 570 is a rebrand of the old Radeon RX 470 ($179) which was released more than 4 years ago back in August of 2016.
AMD doesn't keep the models - we know RX 5700 XT is a mid range card, replacing RX 480 / RX 580 but AMD thinks it's Nvidia's higher-tier competitor, hence RX 480 was launched for $229, while the terrible RX 5700 XT for as high as $399 or 75% higher price tag.
My point still stands - AMD's naming scheme is more as chaos and not any logical order or sequence.
Then there are the attempted "titan" like cards, designed with compute in mind and pushed to attempt to compete in fury (great 90's throwback ATI name) and two variants of vega as the high end in both 56 and 64 variants - Every top end sku in amd and even going back as far as when they were ATI (9500/pro, 9700/pro and later 9800/pro) all of them had a full die and a cut down die with the exception being Radeon 7 which in itself is a cut down mi60 die.
Edit: realised im pages back and havent caught up yet
What we saw in the 5700xt is really the start of a new sequence for navi.