Bloggs,
You're talking nonsense. The E in EGPWS is purely GPS & database-based. If an obstacle is not in the database...
What he is saying is correct. Obstacles have been added with better surveys and better data subsequent to the inception of EGPWS. And, there is a "peaks and obstacles" option for additional $$$$ that provides greater accuracy and fidelity of terrain near airports where RNP AR approaches are in use.
There is a possibility that the EVA 777 that came dangerously close to Mt. Wilson near KLAX the past December did not have the many antennas on Mt. Wilson in their EGPWS database. One of those towers is almost 1,000 feet, agl, atop the highest point on that mountain.