I think there is no chance that the DTA codes have changed. That would be a nightmare for Comcast, and there is no reason for them to do it.

If you want to check anyway, and have a silver Comcast remote with a red OK/Select button, you could temporarily change to setup code Cable 1982. That sends the XMP protocol that the DTA uses.   Then change back to 0476 or 1376 to control the normal set top box.

You have to unlock the cable setup code, using the 982 command, in order to change the setup code for cable mode.