Oh I think recruiting goes in waves. I think when some teams have had a number of players in previous years, future recruits may not be interested because they don't see opportunities to play while another team with less recruits have more opportunities (not true across the board, but I have seen waves at schools like that).
New coaches affects a lot. Where their high schools "point" their students has an affect (and that changes often). Influences on high school students as well including their families, where they want to go, etc.
I think the biggest thing as well is that there is more talent out there and thus there are more options especially in Division III women's basketball. I will never forget Nancy Fahey saying to me after I asked her why it seemed harded to win national titles for the Bears now versus then - "there are a lot more talented girls playing basketball now." In other words, more talent at more schools. As a result, there are more options and recruits are constantly looking around. Also I think there is far more awareness of Division III schools outside of the immediate "area" for many. There are numerous reasons for that, but the key being players may be more aware of schools further away and thus schools don't have the same area to pull players from because they are looking elsewhere.
If the South remains "down" for a few more seasons, than I think more is going on. If they return, then the wave idea is more prevalent.