I've not heard of that proposal. Wouldn't that just break all uses of {xy pa} when talking about the definitions of words?
Besides, {me'o} still works, paralleling the use of strings for entry of ISO dates in programming languages. I just prefer {li} because
- It's shorter
- Dates and periods technically *are* numbers in a certain sense; arithmetic can be performed on them, despite the fact that in some ways they don't act like real-numbers, due to the varying length of months and years.