Division 1 schools may have a maximum of 85 athletes on scholarship (football). Thus, athletes transferring in and athletes transferring out affect the maximum number (85). If a school loses 5 scholarship athletes through attrition (transfer, giving up football, academics or whatever) the baseline number of 85 on scholarship is most assuredly impacted.
That said, schools may sign 25 new athletes annually (this year December 20, 2017 and February 7, 2018) as long as they are down to 85 by August, 2018, when all scholarships are finalized. Obviously, 25 a year times 4 years equals 100 so a certain amount of attrition from transfer, academics, etc., is built into the guidelines.
Ole Miss dealt wisely with its impending sanctions regarding scholarship limitations by giving up 3 or 4 scholarships in prior classes. Thus, for the 2017 year Ole Miss limited itself to 79 scholarship athletes. For the coming 2018 season Ole Miss will limit itself to a total of 81 scholarship athletes. Because they planned ahead and self imposed, 2018 will be the last year Ole Miss will be forced to play with less than the full 85 limit. Starting with the 2019 season Ole Miss will have a full allotment of 85 scholarship football players.
As far as the upcoming 2018 class is concerned, Ole Miss and every other school, is impacted by the 85 limit insofar as it must not be exceeded come August 2018. The number of graduating seniors, transfers, and all other types of attrition must be taken into consideration. Prior to the recent announcement of 4 or 5 transfers Ole Miss was going to be limited to signing only 15 or 16 to stay under its self imposed limitation of 81 for the 2018 year. Now, with the transfers that number has jumped up to 21 or 22. This is not brain surgery.