Yippee, I stumbled across a way to end 2FA (perhaps prior to when AmEx would like it to terminate).

AmEx card user for ~20 years, 2 months ago fraud on one of multiple NLL biz plats/golds, account closed, new card mailed. Since then I’ve been required to do 2FA when logging in on desktop Windows PC and for retention calls, not when logging in on mobile Facial-ID device app. My AmEx profile has had my same landline phone # for 20 years, my same mobile # for 5 years.

Landline retention call today, human answered immediately, she confirmed my PIN (which I dislike, I prefer to only enter my PIN to non-human devices), then said “I have to transfer you to our Security Team, I’ll stay on the line”. Security Team guy picked up immediately, before he asked me any questions I said “I’ve been a member for 20 years and I’ve never had to do this 2 Factor Authorization in the past and I think it's because of the recent fraud on one of my accounts and since AmEx can always see the phone number from which I’m calling or the device I’m logging in from, is there any way I can request the 2FA to end?”

He said “let me ask the questions and then I'll look into that.” In this case the 2FA was for him to call my mobile phone while he put the landline call on hold. He called my mobile phone, asked if he was speaking to me, I said “yes, you are.” He ended the mobile phone call, came back on the landline, said “the authorization is complete and I removed the code that requires 2FA.” I said “does removal of the code for 2FA for phone calls also remove the 2FA requirement when I log in on a Windows PC?” He said “yes.” I said “thank you very much, you've made my day.” I logged into my account on my desktop PC immediately afterwards, no two factor authorization required. Happy camper.