I am hoping that one of the phones going on sale tomorrow is. Samsung has a list, but some were tested in Non-US markets. (the list is here: Compatibility | Samsung Gear S3 - The Official Samsung Galaxy Site). My Moto G (1st gen) does not have the goods. I’m hoping the Moto G4 Plus might work. It seems to have the RAM, but I don’t want to drop $ on a phone that won’t work (and I can’t afford the higher-end Samsung Galaxy models). Thanks for your input.
I’m sorry no one here appears to have experience with the combination of devices you want to pair. I would hope the Samsung documentation is accurate.
We do offer a 14-day guarantee on the phone, if you wanted to try it. Or you could send me the Gear S3 to test for you… (kidding!)
To answer my own question, it appears that the Samsung Gear 3S is compatible with the Moto G4 Plus. Rejoice.