As a person who plays BTN as a Main class, I feel this could bring some great things to the gathering classes.
-Pet would serve to break up tedium
-Pet could have an inventory to hold gathered items
-Pet could open up Gathering Specific Storylines
Most important to note is SE is currently trying to figure out how to incorporate Pet Classes and Mount Raising into this game. This kind of idea could serve to fill that Pet Class and Raising aspects. If you allow users to raise their chosen pet and manipulate their stats and abilities it could become a whole new source of game play.