The M1 Pro and M1 Max came out of left field for some, the names did for sure, and I was wrong about the ports, and actually a little disappointed initially, as there are now purpose-use ports on a machine that used to be 100% flexible.
That being said, there are plenty of rumors about Apple in 2022, and I will breakdown my take on what to expect.
MacMini
2022 will see an updated MacMini, possibly with a “Pro” moniker attached. This machine will have at the very least, the M1 Pro and M1 Max as options. However, rumors are flying of a dual CPU version, likely of the M1 Max, dubbed M1 Max Duo. This would likely be the SoC for the high-end machines. They are likely to adopt the power supply from the iMac, and perhaps the 10Gb Ethernet in the power brick if possible. I suspect Apple may, with the power of the Pro and Max chips, start to include 2.5 Gb Ethernet as standard starting at this point. I do see the possibility of HDMI 2.1 with the Duo models, as they will actually have the available bandwidth to drive such a device. The Machine will likely only be about 1″ thick, and use a similar cooling system as the MacBook Pros.
iMac
The more professionally directed iMac will also be coming, likely with the same options as the Mini. I do not see Apple adding ports, save for perhaps a USB-A port to this model. HDMI has never been an option on the iMac, as a second screen would likely want to be more capable. 27″ is likely, but so is a larger model, perhaps shedding the M1 Pro chip from the larger size, and adopting the iMac Pro moniker. Given the heat generated by the M1 Pro and M1 Max, I do suspect at slightly thicker design than the M1 iMac, and possibly the color options, with an additional “Space Grey” version.
MacBook (M2)
Rumors are floating around about a new MacBook Air, without the wedge shape, and a design style similar to the MacBook Pros. Additionally, there are rumors about a new base-model MacBook Pro., to replace the 13″ M1. I believe that these rumors actually point to a new machine, the MacBook. Reclaiming its place in the middle of the Apple notebook lineup, like the old polycarbonate models, and the 2008 aluminum model, but not the horrible 2015 model. This will likely have the new screen tech from the MacBook Pros, but limited additional ports, perhaps just HDMI and SD, along with MagSafe 3. It will have a notch too, for the 1080p Camera.
MacBook Air (M2)
I don’t see Apple making many changes to the MacBook Air, except for an additional USB4/TB4 port on the right side, MagSafe 3, and an SD Card Slot. The screen will likely retain the same specs it has now, and may or may not include a notch for a better camera, or they may keep it as is, as the entry level MacBook.
iPad Pro (M2)
There are a ton of rumors about the news iPad Pro having MagSafe. However, they are all thinking, glass backs and the iPhone style MagSafe, when in fact, it will be MagSafe 3 on the bottom with the upgraded USB4/TB4 connector, with support for multiple screens. It will support ProRes recording and decoding, just like the iPhone 13.
MacPro
Expect a MacPro in 2022. It will likely have a smaller case, something similar in size to the Corsair One. It will likely have the option of the M1 Max, M1 Max Duo, and the M1 Max Quad. It will have several USB4/TB4 connectors on the front and back. 2 HDMI 2.1 Ports, SD Card, CF Express, and possibly 1 16x PCIe slot for future upgrades/expansion. RAM will still be included on package, but there is a possibility that given the use of DDR5 in the Unified Memory, that DDR5 expansion, may be possible, but being used as a secondary memory system, much like L1, L2, and L3 Cache are used in CPUs. However, if an M1 Max, supports 64GB, the Max Duo 128, the Mac Quad could support 256, at a theoretical, 1600GB/s, so there may not be a need for more RAM. I would expect internally expandable storage though, hopefully with M.2 NVMe, and maybe 1 or 2 SATA ports, as Pro users would want to keep as much of their active storage inside the machine to prevent data loss while working.
Conclusion
This is a summary of all of the rumors currently circulating. We will see in the spring if any of this is correct. But Apple does have only 11 months to complete their transition, and are actually behind from the last transition, which was claimed to be 24 months, but was in fact 18.