The forgotten assignment operator “=” and the commonplace “:=”

Question

The documentation for PL/pgSQL says, that declaration and assignment to variables is done with :=. But a simple, shorter and more modern ^{(see foo}

Answer 1

A partial answer to my own question:

The PL/pgSQL section Obtaining the Result Status shows two examples using a special syntax:

GET DIAGNOSTICS variable = item [ , ... ]; 
GET DIAGNOSTICS integer_var = ROW_COUNT;

I tried both := and = and they work both.

But GET DIAGNOSTICS is special syntax, so one can argue, that this is also not a normal PL/pgSQL assignment operation.