I’m guessing that the community college to flagship transfer system is smoother in states where the flagship universities do not have their own extensive branch campus system.
For example, Penn State’s tens of branch campuses directly compete with community colleges. The Penn State Branches cost 3 times as much in tuition. Many students attend the branch campuses because they know they have an automatic right of transfer to the main campus after 2 successful years at a branch. The main campus is much more fun and interesting. I imagine that promise leaves many fewer spots for people who want to transfer from community colleges. I believe most of the PA. community college transfers go to state-owned universities, and not to Penn State main. Those lesser-known state-owned universities have made it easy to transfer from in-state community colleges, because they need the students. Most of the state-owned universities have been shrinking in enrollment in PA.
Meanwhile, most major Va. public universities do not have many branches. For undergrads, UVa only has one small affiliated branch in an isolated part of the state. I don’t think Va. Tech has any branches for undergrads. Therefore, they have been more open to community college transfers.