No, there will not be. The RX 8000 will top at the mid range. There will be no successor for the 7900 XTX. Maybe the 9000 in 2027 will have a 9900 XT. I wish there will be a 8800 XT for $500 to put pressure on nVndia, but with Blackwell 50 series using GDDR7 and RX 8000 using GDDR6, an RX 8800 XT for $500 might make no difference.
The problem is midrange is defined on being "lower than high end", and the 5090 is insane that it drags that line up. If AMD makes an 8800 level card, it'll be a "mid range" card by the extremely wide spectrum of performance, but it's still an upper 1/3rd card.