Ok, so this was my experience....
My chicks did arrive yesterday...but not to my local post office. They arrived to a USPS hub in another town. They were going to sit there for another day and then be delivered to my local PO this morning. They did call me though and said I could come pick them up from the hub if I wanted to. Buy then I was already headed to work but since they are open 24hrs I picked them up around 9pm.
They were in a heated warehouse, in a mail bin, with other boxes of chicks and covered with a canvas. When he handed me the box, it was toasty warm.
All chicks arrived alive and robust. They were well packed with nesting material and two heat packs that were actually almost too hot to hold on day 2. Now, on day 3 they are still warm.
I am holding out hope for your little ones, the USPS is used to shipping chicks even though we feel they could do so much harm...and they could I suppose...but the worker was telling me about the sheer volumes of chicks that come through this time of year and they seemed to really care.
Here's hoping they show up today....fwiw my order from Cackle...which is closer to me, has not updated any tracking info since Monday either