Yes, but! .. if you believe all the chatter from the internet experts, apparently Nikon need a full frame mirrorless due to losing market share in that area!
This was the major gist of comments made after the release(s) of the A7ii and A9 ... they were supposed to be the downfall of Nikon's camera business. When the likes of Sony's A6300/6500 series, or Fuji's or Olympuses cameras come to market, there's not so much Nikoncentric negativity.
These Nikon doomsayers all come out of the woodwork when upper end cameras are revealed, and when Nikon push out the same old same old DSLR tech over and over(ie. D5, D500, D810, Df .. etc).
If you look at the CIPA data(randomly chose the last data figures for the last month reported) ... lower end or cheaper DSLRs sold over the previous month(Jun) and period(Jan-Jun) whereas much higher end or more expensive mirrorless cameras were being bought.
The data for DSLRs is most likely due to discounting or rebates (or whatever) rather than purely lower end DSLRs being sold.
The way I'm reading it using random models types as examples: if Nikon use to sell about 500K D3300s and now only sell 350K D3400s, if there was a huge amount of leakage to mirrorless (of those lost 150K sales), then the currency value of mirrorless wouldn't have increased by as much as it did in that period.
So the summary on the mirrorless front would be something like Sony's A7s, Fujis XT and XPro type bodies ... and even Olympuses higher end EM1s may be increasing in volume by a little bit each which is dragging the value of mirrorless product sales higher.
Obviously Nikon's D610 and D750 would be down in terms of volumes by now, considering they are dinosaurs in camera tech terms .. respectively about 3 or 4 years old now. A refresh of those two models would kickstart that segments unit sales.
I don't think those types of products are the issue, they are considered high value products by Nikon, looking to get D5600 customers to consider the D610 as an alternative.
Another aspect to note about the currency value of cameras quoted in CIPA data is that it's in Yen. And the Yen fluctuates in value. So if there are a lot of older models(eg. D610/D750) still being made, and being discounted it will distort the figures a little too.
I don't doubt that the D850 will be a sales success for Nikon. I think there will be higher volumes of D850 sales, then there were of the D810. D810 was an update, for me the only reason to update would have been for the EFC sensor tech, but then reading about it's limitations it was never going to be an actual proposition for me(and I guess a few more like minded
me's out there!) .. too many $s for not enough features(or updates).
D850 tho changes that .. for me the potentially much better viewfinder(my #1 reason for an upgrade), EFC(if it works better than many have commented) .. focus peaking in Lv mode(could be handy for macro), more pixels(hoping for better high ISO and dynamic range) .. etc.
I need real reasons to upgrade .. I'm not a fan of updating just because there's a new model.
And on every discussion board I've viewed that comments on the D850, there are 3 posts from folks explaining they're all going to wait till the problems are sorted out, for every post from the habitual updaters!
Apart from my D800E imploding at the regularly used 10 pin accessory port, I also had the annoying Nikon battery issue with my D800E too, early on. I eventually got back to the store when I had something else to purchase, and got it changed(obviously for free).
True to Nikon form, the replacement battery did exactly the same thing(reporting no life left in it and not really having as much reserve as it really should .. but the age of the battery reporting as 'dead' is the real annoyance).
I can't be stuffed with annoying silliness like that, and I have no doubt that's it's due to Nikons insistence that we all bow to their battery making excellence!! (<-note the sarcasm there!!) and they try to corner that market using inept camera firmware coding to restrict the use of non Nikon batteries!
It was easier for that debacle to be solved with the acquisition of 'coded' thirdparty batteries .. rather than muck about with Nikon's useless batteries.
The gigantic issue with the camera business overall is not the types of cameras sold today as interchangeable lens cameras, but the complete collapse of the once insane compact cameras(where Nikon would have had a strong presence).
Nikon made and sold more cameras (not much but just a small increase of ILCs) last (half) year.
With the D850 and replacements for the D6xx/7xx and Df that shoudl be coming in the next 6 months or so .. I think the hype they'll get may help sales a little more again .. just as the continuous stream of new mirrorless products helps that market grow slowly.