Considering how little they have in wave 1 to produce I don't think it will slip too much. They likely have all the molds done already for the mechs. By now they already have a base idea on what to produce, and likely will go ahead and overproduce for retail sales (and those who haven't closed their PM) once those start.
that's an aspect I personally would like to hear more about from CG, as it would inform my own estimates.
However in general I doubt that either the fulfillment company nor the factory in China is interested in doing retail warehousing for them, which would pretty much happen in the "overproduction based on estimates" case.
Because either the factory has to store the stuff until exact numbers are clear and then send on the containers to the various QML distribution hubs and the excess to the CG retail warehouse. Or the factory sends estimated batches in containers to the distribution hubs and QML has to send the excess after fulfillment from every hub to CG's retail warehouse.
Both cases sound like a workaround, that is potentially possible if you pay either party for it, but not necessarily probable.
My guess, if they are running retail production it is on separate line with separate containers, which wouldn't help the ks fulfillment but also wouldn't necessarily have a negative impact.
Of course it is just a guess from my side, based on past ks fulfillment processes, but such processes are always hard to compare as each project is unique and can arrange different workflows.