My Lina's age was reset to the beginning of her young adult life when she drank the potion of rejuvenation, and she has not gained a day on the age bar since. I'll update if it changes, but I'm not seeing the continued aging like some of you are. For me, the potion of rejuvenation appears to have stopped my sim from aging further.
Maybe my sim is bugged?
Edit: Nevermind, it started moving again! I forgot that I changed the lifespans from normal to long, so it takes a lot longer for the aging bar to show any green age progression.