There's no way we'd be getting a June release of RDNA 4 without some sort of announcement or more serious leaks. People be rumoring the RTX 5000 cards as a 2025 release, and yet we hear nothing about AMD and their next release is only 7 months out?
Your analysis about performance / size is sensible, but there's absolutely no way we would see a release so soon.
It was 1.5 years for the 5000 and 6000, then 2 years from 6000 to 7000. 2 years from 7000 would be Dec 2024 or later. The announcements also come a few months before; if we were getting a card in June 2024 we'd be hearing about it by now, at least rumors if not official announcements.
An early release would be smart, especially if they don't plan to compete at the high end in the next series of cards; get the folks who'd want to upgrade now, before Nvidia releases their cards in Q1 2025.