Maybe they came from the new AFCAD from another user with correct gate assignments
They surely don't come with our installer.
or maybe a faulty install...
Not possible, the installer completes only if all files are correct, and there are internal checksum to verify they are. If the file was "corrupted" on your system, it won't work at all, not just with ILS reversed.
I'll change them myself with ADE
Not needed, just reinstall the scenery and you'll get the file that comes with it, which is correct.
but I know on my scenery they are reversed, also backed up by Jep and NACO charts.
They might be reversed on your system, but they are not coming from our scenery. As I've said, they are all correct in the AFCAD we supply, and of course I've verified then ONE BY ONE after your report, against the official maps.
Just reinstall the scenery, to get OUR file, and verify it's correct with ADE, by opening the AFCAD directly. If you confirm the AFCAD is correct, even after the installation of the original file as supplied by FSDT, but you still see them reversed in the sim, then you'll KNOW you have a conflict file somewhere.