So looking at that changelog, it doesnt seem like they have fixed other key issues like :
-AI constantly disbanding and hiring regular troops, killing their manpower and economy
-AI refusing to disband mercenaries, causing massive performance issues
-Support rebels being flat out broken (it does not appear to do anything anymore, you cant even support a rebel faction without unrest being present in the province, and the support rebels doesnt increase the chance of rebels spawning, even with a 75% chance to increase rebel progress, it only increases based on natural unrest)
-AI building ramparts in provinces with no forts (paradox pls, it literally took me less than 2 mins to code in an ai_will_do modifier for this, its not hard)
-Catholic CNs having their AI broken due to the treaty of tordesilas (they remain neutral towards EVERYONE in their CN once the pope awards the region to someone, even if that someone is their overlord!)
-CNs refusing to move troops out of the new world to fight in wars
-AI using transports to fight, while keeping their heavy ships/galleys in port or sending them in circles.
-AI building heavy ships even if 100% of their ports are in inland seas. This is why an AI Ming cannot put up a naval fight against a player Japan that builds galleys.
-AI refusing to attach naval fleets to yours when you toggle on the "allow friendly fleets to attach" option.
-AI refusing to hunt pirates or protect trade, even if they are sitting at max sailors with tons of gold.
-AI subjects refusing to drill troops and sitting at 0% army/fleet maintenance even if they are swimming in money and have 100+ gold as surplus income.
-European AI completely ignoring their home region to invade Asia/Africa the moment they take exploration or expansion ideas. Russia also consistently ignores a weak PLC to invade Oirat/Korea due to siberian frontiers allowing them to expand that far.
-AI declaring wars even if they have loans or are on 0 manpower. Tried to mod this, but the declare war action is hardcoded. Sad.
-Nations in the HRE are hardcoded to remain neutral to other HRE nations if they are not rivals, which is why Austria will never attack Trent to complete their mission and why Bohemia will reduce Austria to a few provinces, then proceed to ignore them for the rest of the game to invade the balkans.
-Rebels not benefitting from discipline (the UI shows they do, but its a bug). The AI thinks they do so are scared of weak rebel stacks that cant hurt them
-Rebels sitting on forts forever, never being able to take it because the rebel stack is too small, and the AI will never accept rebel demands, so the AI becomes permanently disabled by rebels. VERY common if you look at the HRE.
-Rebels and AI stacks avoiding each other to play merry-go around forever.
-Rebels only teleport if there is a sea zone they need to cross and there is no land route there. The problem is that when you have Danish rebels in Denmark, and instead of teleporting to the other side of the strait (because Denmark is obviously blocking the strait), they try to walk all the way through Northern Germany, the Baltic, Russia and Sweden to get to the other side. Obviously, they never make it to the other side. And if you have no land route (due to border gore), the rebels sit there and wont teleport, and the AI will just let them sit there forever (since they have no way to reach the rebels).
-AI not updating their merchant placement after they lose the COTs in a node. So if you take all of Ottoman's COTs away from the constantinople node, they will still steer all trade to constantinople to collect there, even if they have only 1% trade power there.
The above is not even close to an exhaustive list of hardcoded issues that cannot be fixed by modders.
And before anyone askes, yes, these issues have all been reported countless times on the forums for many years.