When I start the Italian campaign, it says to hold 2 specific regions and 6 regions overall in order to win.

Here's a link that also explains it: https://totalwar.fandom.com/wiki/Italy_Campaign_(Napoleon:_Total_War)#Victory_Conditions

I'd be surprised if they changed it being so old, especially the Italian campaign, but it's possible. If people are running different versions with different conditions then it does create a speedrunning issue, unfortunately. Technically, people should always run latest versions though.

I'm also quite surprised about it, feels like a strange thing to be changed all of a sudden. That's why I'm asking here, to make sure I haven't missed anything :)

What do you remember it being? From what I can tell, the victory conditions have been the same since at least 2016 (https://totalwar.fandom.com/wiki/Italy_Campaign_(Napoleon:_Total_War)?oldid=20817).

I remember it being enough to take Wien. And if you look at all the runs https://www.speedrun.com/napoleon_total_war/full_game#Italy_Campaign it seems to be the case - including my run. However, when trying the run again, it doesn't seem enough to only capture Wien. Not sure why.

Its not just you. I tried a year ago and found that strat that worked in a run a few weeks before was not enough.

I've just tried the Italy strategy again and it's still working for me.

Also, I think that in your run you do still satisfy the current victory conditions. You take the two specific regions (Alpes Maritime & Carinthia) and you hold (or your protectorate Piedmont-Sardinia owns) 8/6 regions overall (Alpes Maritime, Cuneo, Torino, Carinthia, Valle d'Aosta, Novara, Lissandria, Liguria).