Is passenger rail actually operating in the UAE today?

Partly — and the distinction is the whole point. An introductory Abu Dhabi–Fujairah service has carried paying passengers since 30 June 2026, with fares of AED 55 in Comfort and AED 120 in Premium class (The National, 30 June 2026 — retrieved 2 August 2026). The wider network launch, including a Dubai station, is announced for 30 September 2026 — announced, not yet operating — and the high-speed Abu Dhabi–Dubai project has no officially stated opening date.

From What the UAE Rail Network Could Change for Restaurant Location Strategy — the full reading, with the method behind this answer.