Scrapper, before this season, when a team had received a team delay warning and subsequently made an improper request, they were sanctioned with a team delay penalty.
I believe that the change was made because the rules committee felt that assessing the first Improper Request with a penalty even though it followed a TDW, was too strong a penalty for such a minor infraction. Thus, the rule was changed so that even though a team may have been given a team delay warning, the first improper request will be treated as just that - an improper request. If they get a second IR in the same game, then it is treated as a team delay.
Ref: NCAA Rules 6.2.3.1, 6.3.2.1