I dunno it probably depends on how much you use it and whether it's needed for business etc. If not and your only choices are stick with Z3200 or change printers to Z9+, maybe just stay with Z3200 so you don't need to buy all new heads/inks, which is the real cost. "If it ain't broke..."
But if it's more critical, then I'd probably skip any HPs entirely and go with a Canon or Epson (Canon 2600 / 4600 seems to be a strong option). As you probably already know, HP basically abandoned the wide-format photography market and deleted the entire engineering division that created and supported them pretty much right after they launched the Z6/9..., altho they still peddle the printers

From what I've seen around here, not many people bothered with the Z6/9 series, they either stuck with the legacy Z3100 / 3200 series, or they left HP completely. I'm amazed they still sell them.