A Chiphell forum user showcased the AMD Ryzen 9 5900X running on an older, entry-level A320 motherboard from ASRock. This indicates that some motherboard manufacturers may plan on supporting the Ryzen 5000 series on entry-level AM4+ boards, despite AMD's claims to the contrary.
https://www.notebookcheck.net/AMD-Ryzen-9-5900X-spotted-running-on-an-ASRock-A320-mobo-Fine-wine-A320M-and-X370-boards-could-support-Ryzen-5000-despite-AMD-s-claims-to-the-contrary.502795.0.html