Apple seems committed to an annual release for the M-series family (the January 2023 MacBook Pros were supposed to be Fall 2022). Now that the M-series has caught up to the A-series iPhone chips (M1=A14, M2=A15, but M3=A17, so the M-series are now only a month and a half behind the iPhone), the initial release has to be in late fall. If they released any of "this year's" M chips ahead of the iPhone, it would give a preview of what the phone's going to be (which they won't do - the chip of the year HAS to come out in the iPhone first)...
Unless they go to an "all one day" release strategy, in which the Ultra comes out in October alongside the other three chips, they have a problem. There will be a time when the Mac Studio (and Mac Pro if they bother) are a year behind the laptops. Even in a year where the performance increase is only 10 or 15%, that's not great - and in a year like this one, when they added a bunch of performance cores and GPU features to the Max, they could be in the embarrassing situation where their fastest machine is a laptop.
If they release the Studio only a little behind the other machines (say January), they don't have a long time when the Studio is eclipsed (only a couple of months by the time the top MacBook Pros start reaching users' hands), but they end up releasing it only six or seven months after its predecessor this year (that's fixed in the future if it goes on an annual cycle). They also end up with a situation in which all the excitement is crammed into a small portion of the year, from the iPhone in September to the Ultra in January, and all they have to release from February through the summer is existing chips in more form factors. People will know exactly what the MacBook Air and the Mac Mini are going to be, since the base and Pro chips will already be out.
Maybe that's OK - it'll save WWDC for the software (and maybe some quickie press-release hardware that surprises nobody) - unless they have a new hardware category like Vision Pro or a car. They can use March unsurprising computers like the Mini and MacBook Air, iPads, headphones and the like. This leaves a lot of WWDCs with no notable hardware (unless they have a new category, or if something that is left for WWDC like the Mini or Air gets a redesign)
On the other hand, the Studio is an awfully appealing WWDC release. The developer community loves it, and a lot of creative pros also keep an eye on WWDC. The problem with making it a WWDC release is that it's then 8 or 9 months after the lesser chips, and in the one year in three or four when they add cores to the Max, that's most of the year when the Studio looks a little silly.
I don't know which they prefer - I was a little surprised at the late fall release of three chips, because it causes this problem.