Surely, Zoom levels ARE part of Workspaces…!? Remember, he reports that the horizontal zoom changes as expected when simply switching between ‘A’ and ‘B’.
Though, if I’m understanding the sequence of events correctly, described by the OP, then if you last had Workspace ‘B’ open and you pressed to Update ‘A’ - then both ‘A’ and ‘B’ are now the same; switching to ‘A’ won’t change your view at all.
There is completely new Worskpaces system in Cubase 8.
As I said: Horizontal Zoom is NOT part of Workspaces in Cubase 8.
Btw: there was something like “update” Workspaces in C7.5.40. All (unlocked, which was the default settings) Workspaces were updated automatically all the time. If you wanted to update your locked workspace, you had to unlock it, and lock it back, in Cubase 7.