ETA
In discord one of the Devs says that they are sure it works fine for any save at least from past two versions, advise was (a) it is low prob and (b) one has to wait 2-4 game days between tries.
So going to try this myself
(at least one player succeeded in current using apparently a not-new save so...)
And it worked.
So
1. Waited four (4) full game days [no raids on Tower at all for four full game days]
1.1. Noticed also that three girls head icons had appeared versus when first loaded the new version and the Alchemist Tower raid appeared, showing only one. This seems to be a sign that the Raid is 'ready' [icons being human girl, elf girl, neko girl - I suppose this is saying any of three is possible]
2. Launched raid with max strength - got one girl and some normal potions
2.1 Same day but waiting a few game hours, was about to launch a Dungeon raid for potions, I noticed that while immeidately after successful first raid (2) had only one girl head after the raid (in the R menu), saw the three girl heads back, so launched second raid, got the Succubus Extract along with some other potions and a neko girl.
So - no need to restart on a new save, I was using an old save originating two versions ago (and lvl 70-odd gobs and werewolves)
On other hand I do notice that if one ends up maxed on monsters or gobs and births "stall" due to that, they won't restart even after getting your Gob and/or Monsters below max number unless you take the girls "stuck" in birthing station out (send to slave room) and put a new girl in. Then it restarts.
Same with automation, that seems to break / freeze if one maxes but it will restart if one takes away the stuck girls in the birthing station.
Last thought
Is it general for everyone that in Brothel the stations reset to plain vanilla original goblin table (from whatevver custom selection) or is this just a bug for me. I am guessing general... (small thing but modestly annoying if one likes like I do to customise that to my own preference)