It really is more of an administrative issue on which year they are applied to. An EE can be applied to either year and which year it is is depends on if you have room in the year before...think cell phone roll over minutes...if you didn't use all your 25 a year alotment from the year before you can backdate kids so that you can take more going forward.
The real number is 85. You always have to be on/under that. That means at all times and not just during the season. For example, if you have kids who just finished their final season of football but you are giving them one more semester to finish their degree they still count. Thus you have a limited number of EEs you can take based on 85 minus returning players minus those who you allow to finish their degrees...
I hope that made sense
And fwiw...it's not quite the same thing as "signing"...unlike a LOI it is not binding until the kid actually starts receiving financial aid...he can sign the papers and back out up until he goes to campus and receives aid