Do Monster Surges Count as a Prevented Gate Opening for the Purpose of Increasing the Deep One Rising Track?
Apparently the official ruling is that a monster surge is not a gate opening, it is an effect that occurs instead; and it does not cause a Deep One token to be added.

This page on the Arkham Horror wiki also suggests that adding a Deep One token is an event that occurs at a different time than a monster surge, and offers some additional explanation of the difference!