The article does NOT specifically say after 1 May. In fact, it says there is only one reason double deposit is acceptable- and that one reason relates to wait lists, not dates.
Here’s another article about double deposits:
http://m.huffpost.com/us/entry/is-double-depositing-wron_b_5009949.html
I always tell my kids that anything is ok to do so long as it’s not illegal, immoral, or unethical. While not illegal, there’s two sources that say the practice is unethical.
And here’s another article:
http://www.thedailybeast.com/articles/2010/04/29/the-dirty-college-admissions-trick.html
Here’s another lesson I would tell my kids…
Would someone question your ethics if you deposit at one school? The answer is unequivocally no.
Would someone question your ethics if you deposit more than one school? Some would question your decision and some would not. Let’s agree on that.
Therefore, make the decision that is beyond reproach. End of story.