I think there are two things happening here:
- 開ける read as あける is also the potential form of 開く so theoretically one can say that the “door can be opened”, but maybe that sounds wrong with が
- 開く read as ひらく means “to unravel” or “to open up” or “to unfold” and it’s more related to things like flowers, businesses, etc. It’s less tangible than あく. The potential form would be ひらける, but that to me sounds weird. Maybe it makes sense in some contexts, though.
I did some extra digging and there are unfortunately overlaps between あく and ひらく so it might be more context-dependent yet.