I wouldn't say it's been "chronically" delayed. There has to be more than one delay for the delays to be considered chronic (see Jupiter's Legacy).
But more to the point, Archie has made it clear that Sabrina is not a priority. The TV pilot is a priority. The Dark Circle launch is a priority. I guess Afterlife with Archie is a priority (though it does take a long time for issues in that series to come out). Eventually the release of Archie #1 will be a priority. Then, hopefully, the TV series is picked up, which will be a priority. When will Archie have time to make Sabrina a priority? More importantly, why would they?
I am just thankful Archie vs. Predator is being published by Dark Horse. They will get the books published on time.