Originally Posted by
mpls85
The short answer is no. The new Shimano 12-speed groups require a new Micro Spline freehub, so not a direct replacement for your 11-speed components. The new freehub is only currently available on DT Swiss, Industry Nine, and Shimano wheelsets as well. Not to mention availability of any Shimano 12-speed components is really limited at the moment.
Is there an issue with your current setup that you're trying to solve with a 12-speed drivetrain? Range with the 11-46 Shimano cassettes is pretty wide, and you can always move up or down a size on your front chainring to adjust range up or down.
Another thing to consider- if you are new to the sport and unfamiliar with maintaining/adjusting your bike, the 12-speed drivetrains are much more sensitive to adjustment and expensive to replace (if you're learning via crashing!). I'd keep your XT setup, and just replace pieces as they wear out- Shimano 11-speed parts are super affordable.
You can use one of the HG 12-speed cassettes. the new microspline hyperglide cassettes and chains are just better, but not necessary. Manufacturers want to tell you you need everything from the groupset, but you don't. Same for crank and chainring that can come from a different manufacturer. I wish people would stop giving advice that sounds like you need to upgrade everything to get a specific derailleur.