TL;DR:
The Windows File Explorer is now dependent on Microsoft Recall being installed on Windows 11 24H2 editions and likely later.
This means that if you wish to use newer versions of the Window file explorer, you have to install recall on your system. Recall is a deeply-rooted, non-negotiable feature on all modern versions of Windows.
Solution
If you wish to strip out recall from your system, you are no longer able to use the built-in graphical file explorer and must use a third-party tool, and if you're not allowed to do that on the machine, then you are forced to have recall running on the system as it doesn't appear on any graphical settings pages.
The other solution is to prepare for transitioning into a free operating system such as GNU/Linux with distributions such as Linux Mint which is designed specifically for that transition. You can also run an older version of Windows and refuse to update.
Errata
Turns out that this issue has been exaggerated and that there are ways to disable co-pilot on Windows machines (or at the very least, command Windows to do so). Also it's debatable whether this program does any harm on non "copilot" computers but you can be the judge of that.
Lots of people do it without issues, but it can sometimes lead to issues, most likely that a windows update overwrites the bootloader and you get locked out of the Linux partition. It's worth trying if you're not sure about it, but you can also just run Linux from an external drive while testing it out, which I might recommend more, although it'll be slower to start up/run programs.
Can't help you with the theme sorry, but I have seen some in the past so I guess it's possible.
The website for each distro often has comparability information, the Arch wiki has a huge amount, which more or less applies to other distributions too.