Specifying the M1 max = you are ordering a custom machine = there is a delay because a factory has to build it for you. The machines that are available for immediate pickup are the base level specs as shown on apple.com.
I bought an M1 Macbook Air mid-February. The site gave me a ship date of four weeks later, but actually shipped from China in eight days, and arrived at my office a couple days later.
Given what a mess shipping has been for the last two years, they appear to be taking the "underpromise, overdeliver" route on shipping quotes.
That's pretty common I think. The retailers get their orders in and planned well before consumers can.
In some cases you're finding far flung regions relative to the source having better availability, because they were allocated a percentage of the original supply but are also too far away for scalpers to be interested, so they just haven't gone through it as fast. Australia hasn't had too many troubles with some items that are pretty hard to get elsewhere for example. Getting a 3080 in NYC is probably a real challenge, but I can walk to my local parts store and pick one up no dramas.