There are a number of factors affecting school enrollment, and immigration laws are certainly a part of that. Condo conversions are another. Increasing home prices in certain areas also affects the number of families with children that can move in. Arizona schools are "schools of choice", where a child can attend any public or charter school that their parent chooses, especially if the parent is willing to transport the child to the school. In addition to all the charter schools (over 450 at last count), the tax credit for private school tuition organizations has made it possible for church-run and other private schools to offer reduced tuition.
Public schools all over the state are looking for new ways to attract students. Your local school may become a charter, or convert to a "traditional" or magnet school. It could close--at least until the neighborhood settles out and new families move in. That is very difficult, and doesn't save as much as it looks like it would.
In central Phoenix, we are seeing enrollment drop, partly due to all the factors listed above. As homes change ownership and the economy cycles back up, I hope to see more families move in. Until then, who knows?
I am a governing board member for a central Phoenix district, and we are looking at some really exciting changes to attract new students. I think in the long run, schools are getting much better due to the competition, but there are always growing pains attached!