I haven't played the expansion yet but had a thorough look at all the stuff, the nice new figures, the new leadership cards and everything else. What I wonder is now: Terran and Protoss gain one module slot while Zerg gains two ?! Is that an intended adaptions due to balance reasons ?

I like that the module slots are less than the number of available modules but especially with the new module types, every single slot is precious. I hope that does not give too much of an edge to the Zerg buggers

I'd guess it's a balance (and balanced) change. The Zerg had no Supply Depots or Pylons before, so they naturally needed less module slots. Now however, with the three new module types, they have nearly as much reason as anybody else for building additional modules - and they still have one less slot than both Terrans and Protoss.

I think the change makes sense. Terrans and Protoss barely ever used all module slots before anyway, I expect to see them more filled in future games as well.

Just so. Used them all as a Terran in my last game, those new modules are cheap and valuable alike.