Digital? Yes, all new cameras are; no need to distinguish them from analog cameras any longer.
Single-Lens? Of course. There never was a Twin-Lens digital camera.
Reflex? Not necessarily. Monitors show what the image will be, plus optional effects.
Thus, (D)SLR concept died the moment the internal monitors were invented. But romantic tradition still keeps the old system alive, although looking through the lens does not show what the sensor records. It was very practical with film, but now it has become obsolete, since it requires a mechanical movement, extra space for mirror swing, and added time lag.
As with many other things, wherever the mechanics can be replaced by electronics, it will prevail, and for many reasons.
The future, IMHO, will advance to small-sized bodies with internal and external monitors equipped with very capable zoom lenses, and also systems with interchangeable lenses.
Maybe the flexible lenses will be perfected, such as liquid-filled systems, or there will be some electromagnetic light-shifting / bending replacement for the whole glassware, but I'm pretty sure the whole mirror-clapping mechanics will be remembered only as an recorded archaic sound - for old times sake.
Finally, the answer is no. Not even my current D cameras are SLR, and they do just fine.
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