1stCivDiv

8. A pilot released from his award as described in Section 24.C.7., (above), shall remain in his current crew position. If his current crew position is unavailable for reasons identified in Section 11.I.2.f. (Training), his crew position shall be determined as provided in Section 11.I.2.g.

11.I.2.f...
f. If, due to a withdrawal or removal from training, a pilot would otherwise return to his current crew position but is unable to do so because the position is unavailable for one of the following reasons, his situation shall be addressed as provided in Section 11.I.2.g. A pilot's current crew position is unavailable if:

1. between the closing date of the bid on which he was awarded the position for which he is training and the date on which he would otherwise return to his current crew position, a more senior pilot has been involuntarily excessed from the current crew position of the pilot in training; or

11.I.2.g...
g. If a pilot is unable to return to his current crew position because that position is unavailable as provided in Section 11.I.2.f. (above), the following shall apply:

1. he shall be awarded a crew position in the same crew status as his most recent crew position consistent with his updated standing bid preference, provided he has sufficient seniority to hold that position; or
2. if he is unable to designate a crew position in accordance with Section 11.I.2.g.i (above), he shall be awarded a crew position based upon his seniority and his updated standing bid preference; or
3. if his seniority does not enable him to hold a crew position under Section 11.I.2.g.i or 11.I.2.g.ii. (above), his employment status shall be determined by the Vice President, Flight Operations, consistent with the seniority and qualifications of the affected pilot.

I think these would cover a new hire FO in his current situation, you don't necessarily go back to your previous seat, at least the way I read it...