Nikon’s latest press release about the collaborations with Nissin and Profoto did not provide much information about the new partnerships. Both Nissin and Profoto already have products designed for Nikon cameras. My uneducated guess is that Nikon will no longer develop new flash or lighting products and they want to make sure Nikon shooters can get anything they need from third-party manufacturers. I think now Nikon will actually start providing development support to Nissin and Profoto. where before third-party manufacturers had to do the engineering alone in-house.
The last Nikon Speedlight SB-5000 was announced back in 2015.
The Profoto press release actually provides a bit more information – they talk about “further improved functionality“:
