Maybe this has already been said, but the D850 specs seem to show that Nikon can get a top-quality sensor designed and made to fit its needs, so I think we can can stop worrying that Nikon is hampered by having to settle fpr whatever second-best sensors that Sony puts in its catalog. Maybe at times Canon hampers itself by insisting too much on doing everything in-house, it of course it could always drop that if it fell too far behind in sensor fab ability: Sony would love a huge customer like Canon.
A few posters, typically owning Sony equipment, have been spreading negative views about Nikon for months.
It is a bit as if they thought that Sony cameras are mostly a sensor with a box around it and if the differentiation of the sensor were a mandatory condition for their success. It is sad because Sony cameras are great in their own right.
I continue to strongly dispute the proposition that it would be in the best interest of Sony not to sell their best sensors to Nikon. Very few of the sensors they would not sell in Nikon bodies would end up in Sony bodies. The cross selling btwn these 2 is much more limited than they seem to think. Sony would end up both losing an important income for their sensor division and also indirectly help strengthen the competitor Nikon would end up working with.
And, once again, these Nikon naysayers are very quickly forgetting that the Nikon orders pretty funded for many many years the development of the great sensor technology we see today in APS-C and FX bodies. I am fully aware that mobile phones were another key funding stream, but there is a difference between a mobile phone sensor and one for a DSLR.
The D850 sensor should indeed clearly put an end to this story... but it won't... because now they are coming up with the theory that 46mp isn't a high resolution sensor... and that the real best sensor of Sony will end up in these...

At some point in time, it will become important to get back to photography and to compare the great images captured with D850 to the non existent images captured with a some day to be released super high magical sensor in a Sony body.

Cheers,
Bernard