Consider this: kanmusu wage is so low that Bismarck managed to buy herself a coat and a skirt only after she had started working at two places.
Maybe she just considered quitting KC and work at AL full time because she can see her sister and the rest of Kriegsmarine,have an easier work load,got some cool new powers and during sorties she just had to worry about getting jumped by ambush fleets and air-strikes rather than getting lost due to faulty compass or locked out of certain maps.