Unfortunately.
The next release has about a two season break from now at the time of writing this, since the TV broadcast run in Japan has just ended. (Depending on who you ask, a three season break counting Winter 2022). This upcoming cour also wouldn't show up on this year's AniChart autumn seasonal chart or any searched up query for Fall 2022 anime on AniList w/o the split.
It's just Netflix that took the helm on worldwide releasing it this way.
Shouldn’t it better to change it to “JoJo's Bizarre Adventure STONE OCEAN Cour 2”
If you think about with the current name could also be called “JoJo Part 6 Part 2” which imo sounds stupid
So “JoJo Part 6 Cour 2” is much better imo. Kinda like Mushoku Tensei Cour 2
Or is the “Part 2” part of the official name?
Shouldn’t it better to change it to “JoJo's Bizarre Adventure STONE OCEAN Cour 2” ...Or is the “Part 2” part of the official name?
Using 'cour' certainly sounds better, but for the time being, going to stick to how we classify and standardize naming recent split season anime (countless examples such as Re:Zero S2, Moriarty, SAO Alicization WoU, SnK Final, Spy x Family entries which all have the added 'Part 2' to differentiate it from the first run), unless stated otherwise by official english streaming license holders (See 86, as Crunchyroll refers to it as the Season 2 > Part 2 & as you mentioned Mushoku Tensei, as Funimation refers to it as Cour 2 > Part 2). The title may change slightly down the line depending on how NF refers to it. However until then, its to stay consistent w/ standard split season named entries and other Netflix anime titles that have previously been released into batches by the streaming platform exclusively: namely Gokushufudou (aka The Way of the Househusband).
If you think about with the current name could also be called “JoJo Part 6 Part 2” which imo sounds stupid
Thankfully, it's not officially titled that way. I do get where your coming from though, some fans will call it that jokingly enough. JJBA is synonymous by having parts after all, which makes both the naming & releasing situation all the more bizarre than it needs to be.