I wouldn't assume that anyone knows when, and how many they will be getting.
The minutes the SKU hits the systems, many of the orders will be on back order by default (simple supply/demand)
Similar to the M&P Shield (9) when it came out, very elusive creature.... what ever was released to the distributors was quickly eaten up.
Calling around asking if someone has something, hardly makes you a customer.... walking into a store, asking if they have it, and dropping a deposit down, or paying in full for the next one that comes in.... that's what makes you a customer.
It was just released, and I'm sure it will be a hot seller.... so I'd get ready for a wait, and or visit your LGS who you've established a relationship with, and have them place one on order. If you are an instant gratification type, then visit/call every shop and see what's available.
We've got several of the G42's on order, I'll post what if any are available once they arrive (assuming that the shop ratz don't grab them all). I did this when we had a few 9mm Shield, they went in seconds.