Samsung's beta testing of Android 7.0 on the Galaxy S7 and S7 edge is well underway in South Korea, China, the US and the UK, so Nougat is coming to the current gen flagships any day now. Last year's Galaxy S6 won't be left out for too long though.
A week ago we reported that the update is in development, but judging by a few benchmark entries, it's on the final straight. Apparently, a Nougat-running S6 has visited both GeekBench and GFXBench in the past day proving that the firmware build is nearly finished. The GeekBench entry is one specifically for the Nougat S6, while on GFXBench it's more of a cumulative listing of all S6 models, Nougat included.
The Galaxy S6 family was always going to be updated to Nougat - after all, we're talking less than two year-old flagships. The good news is that this update seems to be scheduled for an earlier release than Marshmallow - the S6 only got Android 6.0 in February this year.
Motorola is already under Lenovo, so Motorola phones no longer benefit from early OS upgrades from Google like the Nexus phones.