I've never heard this, other than ice-water teas. I guess it depends on things that happened in the past recruitment that you didn't know about (like, if one chapter went way over budget in decoration and refreshment, or if another's national provided all of that stuff), and they're doing it to level the playing field.
This year, each group is having a non-decorated party as one of the rounds before Preference. I got a lot of flak from girls in my chapter for approving it, but it helps me in the long run. I'm also VP-Finance, and I don't want to deal with it if they go over budget.