Harman was term-limited out. According to the rules of the House of Reps:
Permanent Select Committee on Intelligence
(4)(A) Except as permitted by subdivision (B), a Member, Delegate, or Resident Commissioner, other than the Speaker or the Minority Leader, may not serve as a member of the select committee during more than four Congresses in a period of six successive Congresses (disregarding for this purpose any service for less than a full session in a Congress).
Pelosi could orchestrate a change of the House rules in Jan but there was no overwhelming call for her to do so for Jane Harman.