I like the syntax for reading what the statement expects to output first, even though I agree that I don’t write them select first. I feel like this might be optimizing the wrong thing.
Although the example is nice, it does not show 20 tables joined first, which will really muddle it.
1. Calling it "RETURN" makes the fact of its later order of execution (relative to FROM etc) less surprising.
2. "RETURN RAND()" just reads more naturally than "SELECT RAND()". After all, we're not really "selecting" anything here, are we?
3. Would also eliminate any confusion with the selection operation in relational algebra.