I haven't touched Pet Battles in nearly 1.5-2 years so I wonder what the Zeitgeist is nowadays on addons and automation. Do people just read wowhead comments still for optimal battle setups? Or is there an addon now that can just suggest an optimal setup (possibly with some move suggestions) and get done with it?
I would imagine it's possible since the gametype is not very dynamic. The fight is presented and the addon system can see the opponents. Therefore it can setup a whole script of possibilities.
Main difficulty I can think of is the extensive list of pet combinations.