Easyjet never announced the initial £5 (to passengers, nor effectively to staff), but I think it was not long before October 2016.
Looking at my receipt last week I saw that the description said £7.
I have checked the website, and it is indeed now £7.
http://www.easyjet.com/en/help/booking/flexi-fares
I'm not sure how long ago it went up.
It's still very hit and miss whether the crew know about it, but my last trip was the first occasion out of twenty when I could not persuade them (it was one of the Latvian wet-leased planes with non-Easyjet crew).
So I have submitted a claim for the £14 for two of us.