Just called DHL and got my tracking number this morning! I've called every day this week. Told the super nice lady in customer service that I had a package being shipped to me from Hong Kong but wasn't able to get ahold of the shipper. She asked for my zip code, last name, address, and then told me she confirmed a shipment. The airbill for the shipment was created about five hours before this post. She told me the package has not actually been picked up by DHL yet in Hong Kong, but at least the airbill has been created (I interpreted this as the shipment just made it to Hong Kong from Avalon's original location and the intermediary shipper is about to make the handoff to DHL. They are probably creating airbills for all packages they got yesterday or today and will ship them off in bulk.)
If that was good news, here's the better news (for everyone waiting anxiously): This is for order 200000348. Second round of batch one orders. And it's on it's way. I'm in Missouri in the United States, and DHL told me that barring interruptions from customs, the package would have a two day shipment time. (So if it managed to ship today, it would be here Tuesday and I imagine I'm one of the further shipping points.)
Now I will specify that I have another order coming (200000402) that was from a little later in the same batch, and there does not appear to be a shipment for this one yet. But at least we know the order 300's are close to being in the air! I'll keep following up on the second order and announce if I'm able to get a tracking number for it.
Keep your hope up!