Have been is the key..
Let say someone who's very active in 2005-2006 and have made many small mods. Maybe not part of any big team at that time which if he/she had been patronized during that time there's no issue that the citizenship will be granted.
But what if only now with the current CdC will vote for someone who have made contribution to the site 5 or 6 years ago but have not made anymore until today.
How will it be ? Do past contributions which goes back to the last decade still counts ?