Like I said, maybe I'm not understanding which "unspecified values" we're talking about. The freeze semantic is a problem when we've said only that we don't know what value is present (typically one or more mapped but unwritten bytes) and so since we never wrote to this RAM the underpinning machine feels confident to just change what is there. Which means saying "No" isn't on the compiler per se. The OS and machine (if virtual) might be changing this anyway. If you know of Facebook's magic zero string terminator bug, that's the sort of weird symptom you get.

But maybe you're talking about something else entirely?