I agree in certain respects--the five-year gap is a bit much--but what led to the stagnation of the relaunch in the first place?
A variety of circumstances. Delays and changes of author on one of the relaunch titles. Changes in the editorial staff at Pocket. The gap between the DS9-R and the other TNG-era books. The Destiny
event. It was eventually decided to bring the DS9-R up to speed with the rest of the post-Destiny narrative. That is what is happening in the Typhon Pact titles, albeit in a rather uninspired manner imo.
One the one hand, yeah, some of these choices, especially the ones in RBoE, don't feel very promising as far as future DS9 stories are concerned. On the other hand, the pieces are still there on the table for a future writer to pick up and put back together. It's a bit tricky because the DS9 crew can't be easily plugged into a standard Trek narrative the way the crews of TNG, Voyager, Titan and others can. So, we'll see. The DS9-R as an on-going story of its own is dead, but I do think that at some point an author will come up with a compelling story for these characters, at which time hopefully we will get a couple of DS9 novels in relatively quick succession.