As I recall, even Geno and CD have said that it's typically not possible to win an NC without top-drawer talent, no matter how good the coaching or how much character and smarts the "pretty good" players have. (Maybe when they made the Final Four in 1991 it was different.) And there is no question that not having Stewart / Jefferson / Tuck (all Top 5 at one point) will reduce the talent level of the UConn roster well below where it has been for the last four years.
BUT ... assuming Morgan leaves, next year's roster will still have 3 players who were Top 5 in high school: Samuelson, Dangerfield, and Collier. You would think that would be enough of a nucleus of raw talent to contend for the NC. The supporting class will include Nurse and Williams (who were around the #10 level, as recall). Ekmark was Top 50, I believe.
So the level of talent for another NC will be there, but it will be "barely there" -- not overwhelmingly so, as we have recently become accustomed to. It's good enough that character and smarts (and coaching) might be enough to be the winning edge.
That should make for a more interesting and less predetermined season that those we have recently witnessed.