For definitive answers, I'd recommend contacting SlickEdit sales. If I had to guess, I'd guess that they would definitely process an upgrade for folks that already bought it this year. if you haven't purchased yet, get in touch with Sales and they'll take good care of you.
If you bought support when you bought slick, you _will_ be eligible for the upgrade. They'll take special pains to be sure they take good care of folks.
I skipped on support oh-so-many years ago and found that it was a mistake. $5/month ($60/year) isn't much, and the upgrades are worthwhile. My $0.02.
Jim