Dear TSC,
Might you want to spend a couple of minutes discussing Spec proposal: add first-load event to replace xforms-ready? I think it would be good to have a decision in place before the auto-fill feature is released (that is, before the event, whatever it is named, is broadly used).
Have the analytics for those ways been shared somewhere? Last I looked a few months ago, I was impressed to see just how many forms use external data. Clearly, it's a deep need. In particular, pulldata is everywhere. So certainly it would be possible to mark some of those non-standards-compliant implementations as deprecated, but I'd expect that actually removing support would be a ways off.
For pulldata specifically, the function could stay and become an official part of the standard as a simplification of XPath queries that do the same thing. I think @martijnr supports it in Enketo on top of spec-compliant external CSV support, for example.