Unfortunately, T-Mobile, like every other mobile phone provider, has a mandatory binding arbitration clause. It does come with an opt-out provision but requires that someone have opted out within 30 days of the first time they opened their account. If a subscriber did not opt-out back then, even if the terms and conditions subsequently change, the agreement is very specific that a new opt-out opportunity is not created.
I opted-out when I signed up a decade ago but I have no proof of having done that other than a website I barely remember visiting. They do not display my opt-out status anywhere and customer service claims they have no access to know whether or not I did.
It might not apply in cases like this where they are actively changing what you are setting up as your profile settings.
I.e., in their arbitration clause they clearly agreed to give users some control over some privacy settings. In changing your settings they are in breach of the clause not you.
This clause bit Patreon IIRC hard, when a mass of people made arbitration complaints in place of a class action. It turns into a financial DDoS pretty fast.
