[jrivera18911]

I doubt it, but is it possible to intercept a verification code that's being sent to a cell phone number that's no longer in service? (T-Mobile)

[4Txe4y33C9zvNhMj]

Not possible since the code won't even get delivered.

[account_]

Only slight possibility the number become for sale with a premium phone number selling website. plus the number still connected to the service concerned, chances are very small.

[G.P.D.]

Can't you just change the phone number related to the account ?

[Dolla$]

Impossible, mate. Except if you get the phone number back from the operator. Spoofing technics doesn't allow to do this =)
Otherwhise you could hack every account on the internet issou.