For me this depends. What I worry about is all the analog wiring hooked directly to the 3300, like a big, giant antenna. Most installs have little analog and we know the paths - IE: it doesn't run all over the building. However, if we hook into old wire that is likely "everywhere" I will hook up the grounding lug.
Also, if there are inter-building copper connections, we ALWAYS put lightening protection on those lines.
I don't know if this is all best practice, but it's what we do.....
-Chak