At the suggestion of some tools brought up in https://discord.com/channels/114736716505546761/1241997706151329883, I started using MS PowerToys for some quicker edits. One of the options it enables is "Rotate Left/Right" into the Right Click menu on Windows.
After doing this, the rotation displays both in the Photo View from Windows and when opening in Photoshop, but on uploads to IGDB, the image still displays as the original orientation.
I would understand there could be issues if this was some community registry edit, but this is directly from MS.