UCONN will be fine for the most part. The only teams that look really imposing now are Baylor and Notre Dame, since both have an outstanding post combination with a great passer from the high post (Cox/Shepard). Jessica Shepard in particular looks like a nightmare now for the Huskies. If Mississippi State plays UCONN, I really don't see how anyone on UCONN's roster has a prayer against McCowan, but on the flipside, no one else for Mississippi State is dangerous.
UCONN has managed fine with smaller lineups in the past, the key is they need other players to emerge as strong rebounders even if they aren't tall. Rebounding is mostly about positioning, effort, and being able to recognize where the ball is going to go. I'd look for Walker to fill this void if she can get out of Geno's dog house. She's a good rebounder and has size and athleticism. Collier is a strong rebounder too and has long arms which helps. Past players who've excelled as undersized rebounders include Faris, Gabby Williams, DT, Barbara Turner, Kalana Greene, etc.
UCONN does have ONO inside, too. From what I've seen, she does look a bit more raw, but her upside is huge. It's likely going to take her a little bit to adjust to the college game, but I think by the end of the year she could be very good.
What you lose in Stevens is a reliable scoring presence inside and a good passing post player. The passing aspect is huge. Stevens averaged almost 2 assists per game as a 6-6 center playing just 20 minutes a night. Losing that, plus Gabby's 5 assists per game hurts big time IMO. Walker/ONO/Camara are likely not going to be as good at finding open teammates (and keeping turnovers low) as Azura. I think this will be Geno's most challenging season since maybe 2011-12 when they lost Moore, but UCONN will still be a heavy Final Four favorite and should be the #2 preseason team in the country.