I received a "heads up" notice from Holderread about 3 weeks before shipping, but I got a ship date, plus 2 backup dates. So it is narrowed down to a 3 week window. It was nice, though, their notice of shipping date came with a multi-page booklet of instructions on how to care for the ducklings.
Holderread says they will email me the day my ducks ship to let me know they are in the mail, so I can be watching for them.
Another breeder I ordered from is supposed to ship in May, but I've heard nothing from them, other than having my bank verify that they cashed my check. I suspect that my only notice is going to be the call from the post office to pick them up.
The chicks are not machine tooled or poured out of a mold, so your ship date is doing to depend upon how successful the hatch was and whether or not the hens are laying.
I've never heard of the hatchery you ordered from, so I don't know anything about them. I do know that sometimes the people who answer the phones are just employees and sometimes they don't really know much about what is going on in the hatchery.