The reason, which I agree with, for bound items to activate the collection is to prevent people just passing overworld items around. Having them bound means they cannot be passed around. Deconstructing them also ensures that is the case, but it does not trigger the collection.
My crystal ball tells me two things.
1. There is going to be a lot of complaints about people cleaning out their inventory after a dungeon run only to have forgotten to quickly put it on, take it off, then decon it. Overland sets are not bound until equipped, dungeon/trial sets are not actually bound until the timer has expired.
2. An addon will appear that will scan any uncollected sets, force a put on, then restore the prior item.
Given the items made by this process are called 'Reconstructed' it implies the item was once 'Deconstructed'.
If the purpose of 'bound' is to ensure they don't get passed around (which I agree with), deconstructing an item will satisfy this, as it no longer exists.
TL;DR - Have deconstructing an item activate the collection the same as having a Bound item would.
Equip = nobody but me can have it
Deconstruct = nobody can have it