If that suits your needs, then sure, but personally, I'd choose a tablet PC for its versatility, broader app selection, and to avoid the challenges posed by Google's APIs within what I see as a problematic ecosystem. I appreciate my degoogled phone, but it's still quite common to encounter apps that heavily rely on Google's services

Most definetely, i would strongly suggest the Supernote, if you want there are also android options like Onyx, but those are more similar to full tablets than just to a study tablet / productivity device

I'm a huge reMarkable fan; we have two in our house, and use them for everything. They run Linux (and can be ssh'ed into), and the feel is amazing - there's tactile friction, like writing on paper with a pencil, not slick like writing on a glass tablet with a plastic nib. You can install extensions on them... they're just awesome devices.

one of the preinstalled os options is manjaro so yes it can run arch

Probably as its the same as any x86 device

Pen support on linux is amazing. On the T935 it worked without any setup and was much better than on windows in terms of input lag and turning the touchscreen off/on properly.

I used Xournal++ and while the UI is a bit small on a 13" 1080p screen, it worked perfectly.

Now I remember another thing you should probably look out for: Don't get anything with a higher resolution than 1080p. Fractional scaling on linux is basically not a thing, so the resolution determines the size of any UI.

I've owned both an X220T and a first generation Yoga. Each has different pen technology, but both worked out of the box on all apps on Linux.

Rnote is a good app for handwritten notes on Linux. Xournal++ used to be the one recommended, but the UI is not great. I still use it occasionally to mark-up PDFs, since I don't think Rnote is quite there on that feature yet.

Nothing quite compares to OneNote for organizing notes, however, since it has built-in OCR and you can search your handwritten notes. Unfortunately, there is no Linux implementation of it that supports inking. I've seen people say that OneNote 2010 works through WINE, but I couldn't get it running. I also tried an Android emulator to use the Android version, but it didn't work with my high DPI display and crashed a lot.

I had a little trouble with a convertible and it's touch screen, where it wouldn't disable the touch screen when the pen was near the screen, so my palm always made xournal.scroll away.

Turns out there's an easy fix: the software responsible for touch and pen handling (libinput) does support disabling touch when the pen is near, it just couldn't figure out which 2 devices belong together. A minimal udev rules file and a reboot fixes it, but the IDs depend on the hardware.
Fortunately it has since been fixed upstream, so udev rule hacks are not needed anymore unless you run a distro that runs ancient (~2 years, but it varies) packages, like latest openSUSE Leap.

Yes. A Pixel Tablet was released recently. GrapheneOS (a good privacy-focused custom ROM) supports it too. And iirc the tablet supports USI2.0 stylus. But it's 500$ US brand new

Well if I have a tablet, it wouldn't be for Linux based apps, unless maybe some SSH/terminal stuff anyway. The apps mentioned would need to update to properly support tablets, if they haven't been yet.