Not coalescing around None-aware

But the flipside of assume-the-idiom-without-fully-reading is that it's easy to miss slight deviations from the pattern. When that happens it can often take quite awhile to spot the difference because once our pattern matching machinery is fooled, it can take quite awhile to "unmatch" it.

I also don't think it's fair to say that special syntax always increases mental load. Your pattern matching machinery will work on the special syntax just as well as it works on the fully spelled out syntax--actually quite possibly better since there is less risk of false positives. As someone who writes Java for a living, I think it'd be a good trade. Java already has ternary operator but I'd still welcome a more specialized operator like this.

> There are many patterns in programs and languages that a reader doesn't literally read and parse any more after getting used to it.

You're mixing cause and effect.
"verbosity" is not about "how easy it is to read something", it's about the number of tokens/words needed to say something.
Then based on your familiarity with a given expression, the verbosity will have a varying impact on your parsing/understanding speed.

Note though that it will never be as fast as the "??" operator. In big part because you need to check that the words are what you expect them to be (Is the "data" after the "if" really "data" or is it "date" or "dota"? Is the "None" really "None" or is it "Note" or "Noon"? ...). Because of the more limited scope of "??", some of those questions just become irrelevant / have a single and necessary answer.

And that familiarity goes hand in hand with Zorro's comment. The "??" operator, while initially not expressive, will become more expressive as you get familiar with that construct.
Familiarity will make things more readable in all cases, either by making things appear more compact/less verbose by skipping some parts, or by making them more expressive as it gets more ingrained.

> The big advantage of the verbose form is that you can *also* read and understand it, if you don't know the pattern

And we are back to "compact" vs "expressive". One is expressive but verbose, the other is compact but less expressive. One is more readable for newbies, the other for veterans. And people don't agree where the balance point should be.

> Saying that people don't have to [learn] ?? is also wrong, because other people will use it in their code and examples that Newbies will read

Nobody said anything like that. Everybody has to learn. Even the long expression needs to be learned for that matter, because it's not common to have the true-statement on the left of the "if", or that statement that returns a value ("else default") (*). The amount of learning effort is not the same, but it's still there in both case.

(*) more specifically, in most languages, "if" is a statement, which cannot have a value, while here in python, the "if" is an expression, which do have one.