I mention it because others continually refer to it, even though there's no VBI in digital signals. Yes, there's VBI in analog broadcasts. That VBI info is inserted on analog broadcasts only and may appear when that analog signal is converted. It is not in the video signal from video tape, as that blanking time is used for head switching in the recorder. The VBI data is inserted at the time of broadcast. This means the noise comes from elsewhere and not related to VBI, even though it may look like it. As I mentioned, I have seen that on original 16:9 HD content, which was not converted from an analog. Unless the signal has been converted from a broadcast analog signal, it's not VBI and calling it such is just as wrong as talking about analog record artifacts on an CD that was never mastered in analog.
Once again, if the digital signal did not originate on an analog broadcast, it's not VBI. To claim otherwise is to provide misinformation.