I think it is safe to assume that Yifu is not holding back the chips for the sake of the Avalon batch #3 customers, that batch is almost completed and the risk of law-suits is too great that he will gamble with it. It is highly probable that chips do not exists at this moment otherwise he would have shiped at least some quantity to stop the commotion.

Key questions is: What is the reason that Avalon doesn't have enough chips to ship? We can only try to guess, so these are few assumptions and some data to back each one:

1) Yifu doesn't have enough money to pay TMSC manfacturing the chips.
Data:
- He stated several times he doesn't control BTC address which received the payments. At the moment we assumed that he received cash in exchange for the control of it, but fact that funds are still siting on that address unspent is puzzling.

2) Yifu is not in control of Avalon design and the data needed for fabrication.
Data:
-  Members of the Avalon team had several confirmed disagreements, and even the chip designer carrying the nickname "Gridchip" was allegedly trying to find another partnership instead of Yifu's. It is also unclear how is Gridchip connected to the giant delivery of Avalon chips to Russia, it may be possible that he is in some way involved in that deal apart from the rest of the Avalon team. Could it be possible that delivery caused permanent split, and Gridchip took some data with him which is essential for chip manufacturing?

3) ... (feel free to add your own)