if you recharacterize, the deferrals are treated as after tax, so you get a 1099r and you pay taxes - in your example - 2016, the year they "took place"(as ETA indicated). otherwise, by your logic, such contributions would be ignored entirely in 2016, but then show up in 2017 in testing!
by the way, let's say your plan has a last day rule or hours requirement for match. normally, people who fail such requirements would not be included in ACP testing, but once you add after tax, since those people could have made after tax at any time during the year, they are included in ACP testing, which of course puts more 0s on the test, making harder to pass ACP testing. plus you have move an amount from ADP test to ACP from HCEs, making it harder to pass ACP testing, so you might not be accomplishing anything with such a strategy.