Well, I guess it depends, how you define future:
Seen (really) long term, my guess is: No, no future for DSLR (in actual usage). Longer life in nostalgica.
The ability to change lenses might stay much longer - don't know if the core platform business component of Nikon, the F-mount, will be flexible enough to survive into future systems.
I consider myself to be a member of the "old school" - my point of familiarity and experiences are the SLR and D-SLR. Measuring and comparing many of the new developments against my personal "reference".
I still have issues with the slow startup times of mirrorless systems, can't accept the time lag in the EVF versus and optical viewfinder, find it hard to use an EVF in night photography and I am constantly suprised how bad battery life is in mirrorless systems (vs. what is already available).
Yet, I will not be the future for Nikon. I will most likely die earlier than the new customer generation currently growing around the planet. Born almost with a built-in familiarity for touch screens, a point of speed reference a mobile phone provides, an image quality experience many of us would say no to, priorities and patterns unfamiliar to many of us. Coming from this angle, a mirrorless system is a significant step-up. It is fast, provides incredible image quality, is flexible with lens changes, no need for getting to "fullframe" sensor, as they haven't experienced the old film days many of us have fond memories for.
There is an easy test to find out which camp someones belong to:
Put a D-SLR on a table. Ask a few persons what they see on the table.
If the response is "a digital camera" -> this person most likely belongs to the "old camp"
If the response is "a camera" -> you might have a millenial in front of you
Now ask yourself: What is on the table?
rgds,
Andy