as a guess, it would be probably those E's that are anywhere between around 42k-84k that would have made SE. Given that currently, E's are anywhere from 30k-84k, i'd say
most of the E's would qualify (and of course, most of the P's would make E's and many basic members would make P's).
Hey.... if Aeroplan was so interested in inflating tier memberships for marketing purposes, why not... hmmm... never mind.