Read the note again... they're not saying that being on UMA overseas will cause your call to be billed at an international roaming rate; they're saying that there was a loophole where if you made an international call from a UMA connection anywhere, you would get charged at a domestic rate (or out of your minute pool) and that loophole has been closed.
AFAIK, UMA calls made anywhere in the world are not considered roaming.
T-Mobile USA, Inc. offers many devices capable of making phone calls over a Wi-Fi network. Wi-Fi calling provides T-Mobile customers with an alternative that enhances the coverage they already receive from the T-Mobile network. When phone calls are made over a Wi-Fi network, airtime, usage and other charges including international long distance apply as outlined in their rate plan and the Terms and Conditions of Service. T-Mobile has previously offered unlimited domestic Wi-Fi calling for a flat monthly rate but none of these offers have included free international long distance calling. |
Some customers discovered a way to use their T-Mobile device to make international long distance calls over a Wi-Fi network without paying for them. This has now been stopped and these customers are charged as provided in their rate plan and Terms and Conditions of Service for all phone calls made over the Wi-Fi network. Our customers will not be re-billed for Wi-Fi calls that were previously provided for free. We are working with our customers on a case-by-case basis to address any concerns specific to their account.