This is what I found on the IHSAA web site, it does not specifically discuss your situation. I would say that it comes close with section G. if that section applies, then they would be required to FF that weigh the rest of the team tourney.
VI ELIGIBILITY OF PARTICIPANTS
A. To enter in his/her weight class he/she must have achieved a minimum of 6
qualified weigh-ins throughout the regular season as prescribed in the 2008-09
Weigh-In Regulations that can be found at www.ihsaa.org or www.ihsaa.net.
NOTE: A weigh-in at a multiple dual or tournament shall be counted as 1 weighin
of the required six even if the tournament contains more than 1 day of
wrestling.
B. The above requirements shall not be reduced without expressed written consent
of the IHSAA. NOTE: Additional team members in each weight class may be
weighed in at meets for the purpose of meeting minimum weight classification
requirements for the state tournament series.
C. In order to wrestle at any level of the team tournament, each participant?s name
must be entered on the Official Entry List that was filed with the Commissioner
NO LATER THAN 4:00 P.M. on Tuesday, January 20, 2009.
D. Each team may weigh in a maximum of 24 wrestlers at each level of the team
tournament.
E. Participants in the team tournament will receive an additional one pound allowance
at the team regional and the team semi state events only. This additional
allowance is not valid for any portion of the individual tournament.
F. Wrestlers must be ready to report to the scorers table immediately when called
by the referee. The wrestler to be sent to the scorers table first, who then cannot
be withdrawn or replaced, will be determined by the pre-meet coin toss.
G. If a school submits an entry for a weight class prior to the start of a match and
subsequently forfeits that weight class, that weight class shall be forfeited throughout
the rest of the team tournament series.
Note: A wrestler does not have to wrestle in the sectional in order to be eligible to
compete at other levels of the tournament. Likewise, a participant is not required
to wrestle at the same weight class for each match of the team tournament
series.