My concrete suggestion for cloth vs. paper as evidenced above, is that fabric uses the 0 (solid) mat_state and that paper uses the 5 (Pressed) mat_state. What are the other cases we need to cover? That is do we need to answer much more for DT... I'm guessing leather vs. parchment - it will be no surprise if it is the same. But anything else? It can't be too much or users would be saying something...
Not sure how (or even if) you are thinking of coding it, but could it be structured so the default is null and special 'elseif' cases are added in the few instances where they arise (or the other way around)?
Don't underestimate the solidness and overall accuracy of that wiki entry. The wiki list is incomplete as of a couple of versions ago, since no-one has updated it. However it should only be inaccurate with the stuff that has been introduced into the game in the last few updates, books, scrolls, quires spring to mind (note the contemporaneity with paper). It is definitely missing the artistic forms and (strong guess) instruments will be handled differently - there are additional potential problems for DT here since these are procedurally generated per world. My guess is that paper is cloth but just with a different mat_state, so a dwarf will get a preference for 'cloth' and then rng decides if this is paper or fabric but research to confirm is needed for the wiki. Similarly with leather.
But honestly I think DT is probably up-to-date there. Splinterz definitely added some of these things. I think cloth/paper was just an oversight that never got tidied up as his involvement wound down. The dialogue may at first sight look a mess but it is pretty comprehensive once you get used to it. (That's not to say it could not be improved.) However new stuff will arise, if not with this coming update in a month or two, then definitely once we hit 'Magic'.