In Burning Crusade, all hunter pets should have an attack speed of 2.0 (unless under the influence of Cobra Reflexes).
On Petopia we’ve had multiple reports of new tames having faster attack speeds, so it appears they haven’t been standardised.
Reports include Broken Tooth, and the Winterspring Frostsabers (unclear which, but probably all). So far the reports have all been consistent with NPCs that didn’t have 2.0 attack speeds in original Classic.
Unfortunately many of the reports haven’t given the original names of the beasts, but hopefully they aren’t needed and you can just standardise them all.