Yes, the Nikon Z8 works with the Sony Tough G 128GB CFexpress Type B — with conditions (see below).
Nikon Z8 Slot 1 accepts CFexpress Type B; Nikon's own Approved Memory Cards page recommends VPG400-rated cards for N-RAW 12-bit and ProRes RAW HQ 12-bit. Sony Tough G 128GB CFexpress Type B's VPG certification could not be confirmed -- Sony's own spec page 403s, and independent research indicates only the larger CEB-G960T/CEB-G1920T variants are VPG400-certified, not this 128GB card. Peak write of 1480 MB/s is not evidence of sustained performance -- verify this card's real sustained write speed or VPG rating before relying on it for N-RAW or ProRes RAW HQ.
Conditions for compatibility
Fits Slot 1 (CFexpress Type B). Sony Tough G 128GB's VPG rating is not confirmed in the DB -- verify VPG400 before relying on it for N-RAW 12-bit or ProRes RAW HQ 12-bit (Nikon recommends VPG400-rated cards for these modes).
“We recommend the following Type B CFexpress memory cards”
Last verified:
Compatibility inferred from spec rule (citations above are manufacturer-verified)