Aye, by setting every single future topic “to be tracked”, that equals a lot of bells and whistles going off you would not wish upon your users. 
My fix came eventually; not directly.
Since I started that topic you linked above, the UI now colors the titles of topics not yet entered in the topic listings.
EDIT – In further hyperfocused thought, “read previously” is analogous to “topic that was created pre-registration”. Either way, a black title sans 
tells me there’s content to plunder I have not yet thoroughly plundered. Context and whatever my inhibited organic memory managed to save in browsing will let me know if this is “read previously; has new posts not seen yet” or “this topic predates me (*grunt*) via registration date, but it got some goods you have yet to predate.” I consider my initial gripe in the aforementioned topic resolved. And much obliged for that–Discourse Dev Team and Volunteers–considering I made this edit in pure elation over these now-default visual, immediate prompts to denote distances in time for topics and the replies within; something that eluded me prior from my lack of natural cognitive awareness for time itself.)