A: Yes, and Chrono-FRED can take a Voluntary Re-assignment to replace his mission as well.
Archives
Q: Can Voluntary Re-assignment be used to replace ChronoFRED’s mission?
A: Yes. You can also make the Head in a Jar’s Parents Never Meet.
Q: In ÜberChrononauts, what happens to Chrono-FRED or the Head-in-a-Jar when their goal is complete?
A: When you get a FRED/Head victory, you take that Mission/ID for your own, and discard both the Gadget and your own uncompleted Missions/IDs. However, if you have FRED or the Head but accomplish your own Mission or ID, you reveal your card, discard your extra, and then simply retain the Gadget. At that point, it becomes useless to you; but FRED and the Head retain their mission/ID cards, and they stay in your possession. The Head is still who he is, and FRED is still programmed to complete that Mission, so the Gadgets stay in play as usual.
Q: In ÜberChrononauts, can the Chrono-FRED or Head in a Jar allow you to win without completing the other two parts of the game?
A: No. If you accomplish FRED’s Mission and/or the Head’s ID then you simply keep that Mission or ID card as if they were your own. You still need to complete all three win conditions.