current status (left), saved, immediately loaded (right)
all population types are affected, albeit those with lower residents numbers might lose only 1-2 (or none)
i have yet to notice this NOT happening
to ensure there cannot be any unfulfilled needs, i even tried with trainer where i set unlimited money+influence+goods, but still population is lost
happens on both a game i started on v12, as well as a game originally from v9