The posters above in this thread briefly mention Olivia Nelson-Ododa, and do not mention Stef Dolson at all. Both are good examples of "true centers" who developed their games at UConn, and who have had lengthy pro careers. ONO just signed another contract.
And then there was and is Tina Charles. She may be a "4" in the WNBA, but she was a 5 at UConn, and she developed her inside skills well enough to be the #1 overall draft choice when she concluded her college career, and she led the league in rebounding in her first year in the W.
I think the claim that UConn doesn't develop "true bigs" is manifestly inaccurate.
@oldhusky , you say that "The difference maker, however, would be a rotation worthy backup 4, that could also play more than just the backup minutes behind Sarah". Again, I would point to Morgan Cheli, who at 6-2 is big enough for the role that you describe, and is versatile enough to play 2 through 4 as needed. Unless Geno knows that she won't be at full strength next year (and I doubt that is the case), she should be as good or better than anyone who comes in through the portal -- especially since she knows the UConn offense and defense and won't need to learn a whole new system.