I personally don't think Del Rosario is going to contribute for a year or two, from what I've seen of her. I think it will take her a year to adjust to the speed of the game at the college level. Big's especially take a bit of time to adjust to the college game. Even if I'm wrong, a 3 man front court rotation is far too short with someone as foul prone as Reese IMO. I expect them to pick up another big in the transfer portal for this season.
Van Lith averaged more turnovers than assists this year playing point at Louisville, compared to Morris who has always had a pretty good assist to turnover ratio. Everything you described that you expect to happen is a pretty big leap collectively in the offseason. Yes if Hailey Van Lith improves her shooting percentages significantly, improves her passing, decreases her turnovers, and is ok lowering her usage rate and playing 2nd or 3rd fiddle in her senior year, sure she could be as good as Morris. But those are a alot of if's and best case scenarios.