Update: turns out these were actually just one-offs made by Google and seeded to some Samsung workers (i.e. keep moving, nothing to see here).
— Evan Blass (@evleaks) June 7, 2018
About Gear S4 (probably called Galaxy Watch) Based on Android Wear, 470mAh battery, PLP package, it is expected to have new UX interaction and blood pressure measurement.
— Ice universe (@UniverseIce) July 6, 2018
Ice Universe, another prominent insider who often leaks accurate information on Twitter, has reignited the rumor by offering up some specs. According to him, Samsung's next smartwatch will likely be called Galaxy Watch, not Gear S4, and will be based on Google's Wear OS platform. He also said it will have a 470 mAh battery, PLP package, and a blood pressure monitor.
So which will it be, Tizen or Wear OS? That's the big question, and as of right now we have two conflicting reports by two people who are fairly connected to the mobile scene. The more recent tweet says the Galaxy Watch will run Wear OS, so we lean towards that being the case. We wouldn't bet the farm on it, though (not that we go around betting farms).