First off you did not have to do that, according to Tier 2 Cisco TAC. I just upgraded from 8.x in 2 steps without an issue. Second off, when saying "removed" did you mean 5500-X series? Because 5510, 5520, etc. still have the version as recommended and available to fix the IKE vulnerability. And the last thing I'd like to mention, if you have access to TAC, what is the point of asking the forum for help and then "correcting" the received advice?