This exact thing is irrelevant to Asahi; the reason they don't support suspend-to-disk is that their drivers don't support full reconfiguration. This is a difficult task, as is "true suspend," because Macs have tons and tons of peripheral SoCs running firmware with their own SRAM, so resuming from suspend or hibernate creates a delta between the firmware state and the system state. (and, before the usual Apple trolls show up, this is true on x86 lately too, but on x86 the driver and platform interface is more standardized to support these kind of state changes without as much OS support).

Needing a way to securely verify the hibernate image is ALSO a problem, and one of the reasons Asahi haven't focused on suspend-to-disk, but it's not the first-order issue.