ASUS has apparently begun listing motherboards on the as-of-yet-unreleased, as-of-yet-undetailed AMD A520 chipset. Lower in the chipset rung than AMD's X570 and B550 chipsets, the A520 is expected to not offer any dedicated PCIe 4.0 lanes by itself - at most, motherboards will support the same 20 PCIe 4.0 lanes offered by AMD's CPUs, with the rest I/O being PCIe 3.0-based in order to further cut platform and chipset costs.

All of the A520 chipset motherboards listed by ASUS seem to be in the mATX form-factor - which again makes sense, as having the most basic chipset in order to cut costs and then using the same PCB real-estate as more expensive chipset solutions doesn't seem like a wise choice. The listed motherboards are the
PRIME A520M-A; PRIME A520M-E; PRIME A520M-K; TUF GAMING A520M-A; and TUF GAMING A520M-PLUS. As you can see, these motherboards are set in the ASUS TUF and Prime product lines - there's no mention of any Strix-branded products.