I think each state sets its own qualifications, but there has been a general trend towards greater restrictiveness as college tuition has risen over the last 30 years. The salient points are that one can’t be assured of qualifying in advance, and qualifications are subject to change at any time prior to establishing residency. Therefore, matriculating at an OOS institution that one cannot otherwise afford on the assumption that residency can be established for upperclass years is a fool’s errand.
Note that this would not seem to have application where a college had furnished a written promise of in-state tuition; that’s a different matter.