Thanks for the question. Let me try to remember. (Edit: I just realized I'm pretty late replying. Sorry about that)
I had the program EA App installed at the time I ran the MS Uninstaller Troubleshooter. In my Downloads folder, it is called "MicrosoftProgram_Install_and_Uninstall.meta.diagcab" (same as yours).
I selected Uninstalling and then found EA app on the list. Let it finish and restarted.
If you don't have it installed, I would try to use the MSI installer version. You can also delete the files in your Programs Files folder(s).
Then I opened Epic Games launcher and saw it didn't detect that Jedi Fallen Order was installed (because it's an EA game). I clicked to install it, and Epic said it needed to install the EA App. I figured why not let it try. It worked to install and showed me the sign in box for the first time. Played my purchased EA games then.
But I never had an issue with installing or uninstalling the EA App program. I just couldn't open the program after it seemed to successfully install.
I spent a bunch of time going through the other boards and topics on here and trying stuff. I hope that helps you.
Here's the topic I opened and posted more of my steps (watch out for the sarcasm):
https://answers.ea.com/t5/Bug-Reports-Technical-Issues/EA-App-Crashes-after-Installation/m-p/12397368