It would seem like the pricing is misleading, and that in reality when these finally do come back in stock they will not be at the advertised $699 price point. The FE's are simply loss leaders.

https://www.mooreslawisdead.com/post/nvidia-s-ultimate-play

It's unlikely FE cards will become more available. Unlike previous generations, the FE is both likely superior to the AIB models and being sold for less. This created insatiable demand which many suspect Nvidia would rather not fulfill. Instead, the rumor is the FE cards were underpriced for marketing reasons while pushing buyers to the higher margin AIB cards.