Only DSI would have a sense of it, but I wonder how many people are actually asking for a new Evolver. There are two or three requests on DSI's Facebook page under you-know-who's video. I often see others when I poke around the synth sites. But what is the total number? Are we only fifteen or twenty? Are we enough to move Dave Smith, or is it all pointless?
There's still a fair amount of people who like the Evolvers. Currently, there's a thread on Muff Wiggler about the MEK and the desktop version, in which most participants are really enthusiastic about it. The German online music tech magazine amazona.de, for which I occasionally write as well, released an article about all Evolvers in 2016 again, calling the Poly Evolver Keyboard PE Dave's best synth. There's even consensus about it having been underrated at first. And many people also point out the sonic differences between the Prophet 12, the Pro 2, and the Evolvers. So from that I'd say that its unique sound and hybrid architecture are still appreciated today.
However likely that would be or not, though, I would like to see a few improvements on a revisited Evolver. No internal effects for me, as that just takes away space, but rather an analog high-pass filter (even if that would probably lead to getting rid of the pre/post routing option) and an analog distortion, preferably even a drive parameter in the filter section that could rather be used to thicken the sound in a warm manner instead of making it scream. Other than that, streamlined parameter values as well as mod assignment methods, and an OLED screen would be nice. Those would at least be my basic suggestions for an upgraded/revisited version.