Wargaming plans on changing the progetto 46 like the rest of the Italian mediums tanks by removing the gun rammer. The problem is that it means nerfing the progetto 46 directly, so to make sure they don't nerf that premium, they buff the reload to what it would be with a standard gun rammer. The problem is that the gun rammer used a equipment slot, so it had a trade off.
This straight up buff that lets it have a faster reload than the tech tree tier 8 counterpart, and has a free equipment slot for where that gun rammer would be. For my new loadout on the prog 46, I equipped a engine supercharger, vents, and optics. With this loadout (and the supercharger in the mobility slot), this means the progetto can go as fast as the pantera in top speed with similar mobility. What was a downside of the progetto 46 compared to the tech tree counter part has now become negated.
The pantera may still have slightly improved armor, but the tank is higher profile.
This means the progetto 46 is arguably the most overpowered premium in the game, even worse than a Defender in my opinon.
Edit: Link to changes