You can't look just as who a team loses and who they add to project how much they might improve or degrade. You have to look at the classes of the returning players. Freshman improve the most into their sophmore year, then sophmore to junior and then junior to senior. In fact, many players stagnate from their junior to senior seasons and some even take a step back.
If two teams lost no one and added no one and one team was all freshman and sophmores and the other was all sophmores and juniors, the team with all freshman and sophmores SHOULD improve more. And then you have to look at injuries. If a key player was playing with an injury and then they have an injury free season, they will improve quite a bit and vice-versa. Not only is UConn adding more to their team, they have a key player who was slowed by injury last year and they were younger. Mid-season and even mid-tournament injuries robbed UConn of at least two national championships, in my opinion, and it could happen to Baylor as well.
Baylor will have a tough time defensively against UConn. There will be too many weapons. How well UConn contains Griner will depend on whether the refs allow the UConn players to carry out Geno's defensive plan. I know people hate to hear it because it makes it seem like outcomes of critical games are not under the control of the players but the refs, and how they call the game, makes a HUGE difference in who wins a close game between two close teams. Even if you assume they are unbiased and fair, it still makes a huge difference because "style" matters. Will they call the game tightly? Will they emphasize hand checks or will they crack down more on the moving picks and physical play down low? Will they allow some contact with the shooter or will the (Notre Dame) players spend the entire game at the line like it is a game of knock out?