They were certainly considered canon by the fanbase, but that's the problem...unless it was on the screen or made by the prducers of the shows, it's not canon.
Same goes for fans of SFB, who consider it canon for the same reason fans of the old FASA stuff consider it canon: it's more consistent.
Even though the Orion Wanderer made a cameo on a computer screen in TNG, that's about as useful as the appearance of the Millenium Falcon in "First Contact".
Stuff made by FASA still belongs to FASA...or whoever took over FASA.
Means no chances for me to get a Riskadh.
Sadly I've developed my love of Klingon starships from non-canon sources (SFB,SFC, klingon academy, etc) and have no love for the canon ships. Until STO breaks away from on-screen canon we'll only get the same old crap we have now. No SuvwI'QeH, no voDleH class, no pumwI'-class. Instead we'll get BoP's that dwarfs D7's in size, more Negh'Vars and vorcha's.
The D5 would be nice, as well as an upgrade to the Koro'T'inga.