I would offer that the old Tree ID section was in fact "Recognition", whereas the examination regarding taxonomy is in fact a test of "Identification" skills.
I think having both is a fine idea, but let's agree they are different things. If, however, we were to choose between them, Identification, IMO, would be more demonstrative of skill and knowledge than Recognition.
Identification skills can be carried from one plant set to another, Recognition is limited to one known group.
Think of it this way, with education and experience in a certain geographic area I can Recognize many trees and shrubs(when I lived in Nashville, TN). With a measure of proficiency regarding taxonomy and a relevant key, I can Identify virtually anything(When I moved to Atlanta, GA).
The ability to correctly Identify an unknown plant, is foundational to accurately diagnosing it's problems, understanding it's needs, and prescribing it's care.