It's a good idea on paper, but it would be a headache to implement. We already run into issues with importing pets from the armory, and that's live data.
As Dakender pointed out, Databases like Wowhead and MMO-Champion have a good handle on keeping the data from the beta updated, though. They list ALL datamined pets (regardless if you can collect them or not) and their abilities (if available).
Plus unlike WarcraftPets, which specializes in helping players keep track of collections and provides only info on pets, Wowhead and MMO-Champion don't need to worry about confusing their users about a beta pet that gets changed or removed. Personally, that's what I'd be most concerned about if we added beta pet profiles. Disappointing/confusing everyone because a beta pet was suddenly removed or changed.
All that said, we'll still keep this idea in mind. Thanks for the good suggestion!