Sigh... Z may be the final version, or there may be a 100 more before S2 final. No-one knows at this point. I'm sure the devs have this all plotted out, but they won't tell us because plans change, as evidenced by the sudden disappearance of half the interiors in patch Z because they had to do the VW.
We get the damn thing when it's good and ready. That's all you need to know. The devs are not going to come in here and say anything more than they've already done. When it's done. That's it.