Unpopular opinion: Apple will likely update the design but keep the M1, possibly M1X.
A laptop isn't like the iPad Pro and they would not want people hesitant to buy because they are releasing major updates too close to each other. There will be tweaks and improvements, but my guess is iMac Pro - larger with more cores and/or RAM (a la the higher capacity iPad Pros). Then, with the re-design there will be the MacBook Air (possibly being retired or merged with next level up), MacBook (14"), and MacBook Pro (16") with segmentation similar to the iPad. iMac, MacBook/Air will have the Mx series chips, while the Pro devices will get the MxX as with the iPad Line - maybe even a modem with integrated 5G.
Release updates every 2 years or so to get around releasing too frequently and scaring off customers/cannibalizing sales, maybe with occasional MxXS models to keep the "innovation" hype without alienating customers.
ETA: they might keep the "Pro" and not have a non-Pro "MacBook". Again, like the iPad it might be "MacBook Pro (14")" and "MacBook Pro (16")" with slightly higher end features going to the larger model.