I don't think so. It's the same way any new guns are being introduced, regardless of brand. From a manufacturing standpoint, they can only make so many guns in a day. They make what they can, then disperse them the best they know how. It doesn't make financial sense to keep thousands of guns in the warehouse while you make more. Those new guns can be in the hands of customers. If those customers are happy, word of mouth will make more people want one. So it is best to ship out what you have.
I think the first batch of fullsize .45s will go to police and military trials. The compact .40 just hit store shelves. I have yet to see one around here. But I'm sure they will show up before long. I have yet to see a fullsize or compact 357Sig. I don't know when they will be released.
There have been talks of a compact .45, but we haven't even seen a prototype yet. The compact .45 will be the most difficult pistol in the M&P series to design reliably. I don't know if S&W has started working on the design or not. It will take a while to get the design perfected; then it will take a while to get them manufactured and in customers hands.
Be patient my friend.