Even with MacBook Pros and MacBook Airs getting thinner, MagSafe in some form was always doable. Hell, Microsoft practically has that with their Surface line and the port is thinner than a USB-C connection (plus it doubles as a docking station connector).
Like, maybe they made the chassis too thin to accomodate USB-A [though, in my opinion that means it's too thin because USB-A hasn't stopped being useful (and you're not going to sell me on the idea of spending $20-50 on a dongle, so don't even try)]. But, there could've totally been a MagSafe 3.
I'm wondering if, with a return to MagSafe, the USB-C ports will still support charging the laptop. Not all USB-C ports support charging the machine. For instance, I have a Dell Latitude 7390 that has a USB-C port that can be used for docking and charging. However, I also have an HP EliteBook 755 G4 (as well as a bunch of 820 G3s) and those USB-C ports do not support charging the laptop (but they also have dedicated docking station ports on those). So, I wonder which route Apple will take when it comes to USB-C charging on these potential MagSafe-Equipped Apple Silicon MacBook Pros.