I guess the question/responsibility rests with hifiberry folks. Do they want to broaden the market for their boards to other fully pin-compatible SoC platforms? .. which probably gets a Yes/No answer. They're small enough that more sales would be great. Equally they are probably so focussed on Raspberry Pi that they're unsure what anything else might entail for long-term support and that might result in an over-cautious no response. The only way to find out is making contact and asking them. In reality it's probably a small change and pushing something upstream: and in parallel pushing the update to RaspiOS so the required overlay changes are already in-place when the upstream change flows downstream in some future kernel bump.
Entirely up to you if you want to ask them and advocate, but I'll always encourage that kind of thing to happen. The RPi kernel devs are sending more things upstream than ever before, but the pile of technical debt is still large. Hence all help in reducing it is good and .. no worse opinion of anyone for finding something easier to do ![]()