Ugh I got rate limited so I had to make a new acct just to post this reply:

Sure! Like mad libs if you couldn't be sure if _____ was a missing part or the text what was meant to be there. In a mad lib it's obvious, but with code it may be less obvious. You certainly can't just use _ with code. Even the nil code point is allowed in some programming languages' source code (e.g. rust).