I think you got it backwards. The current situation where unset field results in a value is the equivalent of "null", it's the opposite of "getting rid of null". The previous design didn't have that problem.
I might be misunderstanding you, but the current situation results in a “zero” value, whereas “Null” would represent “unspecified”, or the absence of a value. I wouldn’t say that the current spec supports null, unless you’re using a wrapper like the one linked.
It’s the distinction between an optional type and an optional value (default value). With optional values but no optional types, you can’t be certain about the caller’s intentions. It’s a distinction that’s subtle but important, therefore a “gotcha”.
Getting rid of null is a noble idea, because of the headaches that null tends to induce. Optional types (like Rust’s) is a neat way to get the behavior of null without the value of null. Proto3 doesn’t have null, it’s replaced with arcane wrapping that’s arguably less straightforward.
Please let me know if I’m talking past you, it isn’t intentional, just late in the day. :)
