This is like arguing that Big Mom sunk the Sunny because we saw the ships destroyed Jolly Roger in the water lol
Or like arguing that Sanji is wearing an exploding neck cuff because we saw Reiju put it on him
If you haven’t learned that Oda is the king of nonsense fakeouts, you absolutely do not know which manga you are reading
While it's not 100% confirmed Vegapunk is dead, there is still that very good chance he might be.
There is literally four other Vegapunks left, Oda probably has no problem killing off the main one when he still has four other Vegapunks left.
Also Kizaru killing Vegapunk doesn't mean that Kizaru is suddenly this evil monster, he was just simply doing his job.
You say Oda does fake outs which is very true but also unless you are blind, Oda recently has been killing off more characters now.
Last arc we had Yasuie, Orochi, Kanjuro, Ashura Doji, Izo being killed, and a big maybe to Hawkins, Kaido, and Big Mom.
This current arc Oda killed off Cobra, Mjosgard, Shaka, and Pythagoras.
We know this arc will have one big major death and while many thought it was Kuma, it seems like it's going to be Vegapunk instead.
So while Vegapunk's death is still not 100% confirmed, you can't deny the possibility of him being dead either.