When the port is unmaintained, it will probably break quickly. For example, the builder is red right now, because new Wasm instructions were added earlier today that would need to be ported.
There's no point in keeping broken code around, so an unmaintained port should be deleted. If anyone later wants to resurrect it for any reason, they can always go back in the git history to find it.
Deleting the code is not urgent, especially as long as it's still being tested and still works. Even when the builders are removed, we can still give it a grace period (something like 1-3 months, maybe?) and delete it if no other maintainers step up during this time. If you could submit a CL to delete it, that'd be great.
Please keep sending announcements to this list when the official status changes, e.g. when "we plan to give up maintaining the mips32 platform" turns into "we have now stopped maintaining mips32, and the code will be deleted in 2 months if nobody steps up to maintain it".