Well, we'd need FD to comment on that.Unfortunately I doubt that will ever be the case. for Example:
Look at how the System map works currently: Open system map - wait for it to load - wait - wait - system map open. Close it and open it again - the whole load process starts anew.
The key indication for me was the old API was dishing this list out with every call so clearly that wasn't immediately an issue. They later removed it, and quite rightly TBH, as what's the point in dishing out an ever increating list of thousands of (visited) systems over and over typically minutes apart?
But the fact they once showed they could seemingly easily render a visited list to me would imply they could again, albeit via an alternative call that could be as restrictive as you like. eg: Only one call per day/week etc...
And let's be honest, most CMDRs will never use it. And the majority of those that do, will probably use it once or twice ever!
ps: A retrieve of a CMDRs visited list is quite probably going to take a fraction of second (unless their's some bizarre DB reason), and result in the construction of a list comparable in size (probably smaller) to the size of the HTML that's be constructed to show this very web page you're now reading. And it's quite possible, that more IO and processing indeed went on to render this page than it would to give you back your list of visited systems