It was still a form of 433.
It's not. It's very different. form of 4-3-3 is for example 4-1-4-1, when your wingers is playing a bit closer to defence goal. The key reason here is that 4-3-3 does not allow for classic AM number 10 role. Which is exactly the reason why Zidane never played in team that employs this formation as a main one.
He played it at times with Madrid and Juventus too. I know what you're saying but very few teams have ever played a strict 433 with three out and out forwards like Barcelona are currently doing.
There are a lot of teams who play 4-3-3, not sure what you on about really. PSG, Lyon, half of Eredivisie (if not like almost all) etc. Napoli played similar system it was a mixture of 4-3-3 and 4-1-4-1. Out and out forwards is not the main point, the main point is organization of attacks and midfield shape. That's relevant bit.
I said that current Barca if they had Zidane would not play 4-3-3, because there is no place in that set-up for him. They have to use for numver 10 in the middle, France in 98 did. No matter how you classify Djorkaeffs role, the main thing was that Zidane played in the center, he played with a lot of protection behind him, whole 3 players in midfield were tasked with getting the ball back and also he was their organizer controlled their attacks. Same thing in Juve or Real, at least two players in midfield working behind him and he led the play, was playmaker in both these teams.
In current Barcelona that is not possible, but if they had a player like Zidane, it's safe bet, that they would not employ 4-3-3 with 1-2 triangle in the middle and will go find something else, some formation in which AM could fit in.