I don't think this needed to be changed. Really.

The Burattinaios is a weapon with fixed stats that will dwindle down to inferiority when compared to new Pup weapons that are certain to come out as we reach level 99 (and beyond.) Sure, this may still be the all-time best automaton-centric weaponskill weapon in certain situations, but those Puppetmasters who never upgrade from this weapon will fall behind on the master's side which, in recent years with gear upgrades, has become a signifigant consideration. I'm pretty sure Verethragna will be upgradable beyond its current stats and will overcome the power of Burattinaios.
(A similar weapon existed for Monks: Destroyers, which held its own against the Spharai for a long time)

Looking at it in the big picture sense, it's certainly a powerful weapon, but it won't always be the best even at 10/tick regain. A more sensible nerf (I'm only suggesting this because they think it was necessary) would be to make it only 5/tick regain. This is still powerful, but it would also become outclassed in the future.