I'm a bit confused by this category,
When we created our categories and assigned sites to them there was both a degree of ignorance (larger in some areas than others - Geology wasn't I fear a strong point!) and compromise. Geology/Natural has never been totally satisfactory. Many of the "Natural landscapes" are in fact manifestations of geological processes - deserts are results of " desertification" just as karst landscapes are results of rock dissolution. Yet one is in landscapes and one in geology!! Colvin is quite right to point out that tectonics is not represented as a process. Volcanism could be said to be a sub process of "tectonics" . Just as "glaciation" has forms related both to past and present activities then so does "tectonic activity"
Whether we want to reconsider our categories at this point I don't know but, if we return to the "little green man", we would surely want to show him examples of the main geological processes which have formed the world - and that must include tectonic.
However all mountain ranges (and we have plenty) are examples of past or ongoing tectonic orogeny so do we also need specific examples as well? On the other hand the AB eval for Gros morne does use the word " unique". Where the "uniqueness" is related to something significant (as in this case) that would seem a good reason for inclusion in the 400+