Was there any consideration given to whether ruleutils should start printing NamedArgExprs with "=>"? Or do we think that needs to wait?
I didn't think about it? I don't see any reason why it have to use deprecated syntax.
There is one, loading the output into older version of Postgres. Don't know if that's important one though.
I don't think so it is a hard issue. We doesn't support downgrades - and if somebody needs it, it can fix it with some regexp. We should to use preferred syntax everywhere - and preferred syntax should be ANSI.