I'd say from my experience there's a definite possibility - as always YMMV. I'm 24, and experienced a bit of MPB (a cm or two of recession), and that's completely reversed now - mind you this is over 6 years of HRT, not only does it take time for the onset of changes from HRT, hair takes a long time to grow! My HRT included Finasteride. tl;dr, finasteride is mainly prescribed to mitigate MPB in men, but I think perhaps in combination with estrogen it may indeed reverse hair loss to an extent, rather than only slow/stop it.
Hibernation is a good point - the follicles are still there, they're just not active. Keep in mind (this is from my experience) when the hairs start growing back they'll be extremely virgin hairs, almost like a baby's first hairs; very soft, fine, light, gentle. It's not a good idea to go through dramatic things like bleaching, dying, etc., use gentle shampoos and conditions, let your new hair grow big and strong!