I think this may be true. After my last Mac upgrade, the app did not work with either of my phones. It looked like just a timing issue, because the files would eventually appear but the file transfer app had given up and wouldn't let you do anything but quit. Probably a fairly minor bug that for whatever reason they just won't fix.
I really wish they'd just fix it. For whatever reason, the app just fails to connect to my phone. I already made sure it's trusted and tried all of the USB options.
The only transfer method that seems to work for me is adb pull and adb push.