So basically, what you want is to have the ADS also act as a surface scanner, instantly creating planetary maps for all bodies in a system, because visiting each planet to find out whether it's an ice ball or something more interesting is a lot of effort, right?
How about an indicator for planets that "might be more interesting" - so you still don't know what it is yet, but you get a little star that prompts you to investigate further. Metal worlds, earthlikes and such would then show up as "candidates" in the system map (as grid planet) until you actually do a surface scan.
See, now that's a great way to approach things.
The discovery scanners already gather a fair amount of information (probably a little too much really) on everything in range.
So if the information were to be broken down completely so that the discovery scanner gives you a guesstimate of the mass of the body based on its size alongside orbital data and any satellites it may have. Based on those two sets of data it presents a probability chart of sorts of the likelihood of being a planet/small body of X,Y,Z etc.
If a detailed scan is performed of the objects parent star (or planet if it's a moon) then the probability chart can use that information to try give a tighter range of probabilities and it also presents some hypothetical surface conditions alongside body type probability... like:
60% chance of non-atmospheric ice planetoid.
30% chance of atmospheric water world.
Potentially rich in metals with active volcanism.
Within the system map, non-scanned bodies show a generic appearance based on the highest probability type the algorithm churns out but with a '?' marker next to it and a breakdown of the possibilities in the body information to make it perfectly clear what is what... or rather the likelihood that it's really what it seems just from looking at the texture image.
Then once you're in range to perform a scan if you don't have a detailed surface scanner, the results from that give you the exact type of body you're dealing with and other larger information. And from that concrete information the potential for metals, volcanism and other details is re-calculated to give more accurate probability numbers. If you have the surface scanner, then the scan gives you full accurate findings.
Edit: Clearly all this is stuff "For a later time". So for now, just retaining the blank state for non-scanned bodies and making the behaviour a byproduct of intended behaviour rather than unintended behaviour would be a nice first step and help get players in the right mindset for any future reiteration to polish up the concept into something more player engaging further down the road.