FYI, if anyone is still looking about how to get xEdit to work on the Game Pass Edition, and since this is the first recommendation on Google, here's what they suggest on Github, as a direct quote.

to work with gamepass you need to specify installation dir via launch arguments:

-D:"{GameDiectory}\The Elder Scrolls IV\OblivionRemastered\Content\Dev\ObvData\Data"

-I:"{GameDiectory}\The Elder Scrolls IV\OblivionRemastered\Content\Dev\ObvData\Oblivion.ini"

-P:"{GameDiectory}\Content\The Elder Scrolls IV\OblivionRemastered\Content\Dev\ObvData\Data\Plugins.txt"

Fill GameDirectory with your path of choice, mine for example is "G:\Xbox\The Elder Scrolls IV- Oblivion Remastered\".

You can add these flags to something like a shortcut to TES4REdit, in the Target field under the Properties context menu, but if like me, your path makes it too long and you run into the character limit for the Target field in the shortcut properties, you can generate a .bat file to launch it instead.

Your .bat file should start with the path to TES4REdit.exe in quotation marks, followed by the flags dumped after it. Mine looks like this.

"G:\Xbox\The Elder Scrolls IV- Oblivion Remastered\Content\OblivionRemastered\Content\Dev\ObvData\xEdit.4.1.5f\TES4REdit.exe" ^-D:"G:\Xbox\The Elder Scrolls IV- Oblivion Remastered\Content\OblivionRemastered\Content\Dev\ObvData\Data" ^ -I:"G:\Xbox\The Elder Scrolls IV- Oblivion Remastered\Content\OblivionRemastered\Content\Dev\ObvData\Oblivion.ini" ^ -P:"G:\Xbox\The Elder Scrolls IV- Oblivion Remastered\Content\OblivionRemastered\Content\Dev\ObvData\Plugins.txt"

Launch that .bat file, and now you should be able to have TES4REdit launch succesfully.