AHJs have a long rich history of making stuff up as they go along but the NEC (2014, the one we are on) only says you need to add AFCIs if you are modifying a branch circuit by more than 6 feet. That would even allow adding short extensions to the circuits to reach breakers in a new panel without triggering the AFCI requirement but I would still ask.
210.12(B) Branch Circuit Extensions or Modifications
Dwelling Units. In any of the areas specified in 2IO.I2(A),
where branch-circuit wiring is modified, replaced, or extended,
the branch circuit shall be protected by one of the
following:
(1) A listed combination-type AFe! located at the origin of
the branch circuit
(2) A listed outlet branch-circuit type AFCT located at the
first receptacle outlet of the existing branch circuit
Exception: AFCI protection shall not be required yvhere
the extension (~f the existing conductors is not more than
1.8 m (6 jt) and does not include any additional outlets or
devices.
