I've seen this in 31.25: my legacy fort has a room with a glass forgotten beast that I use for crossbow training. I'll station a squad within shooting range, have them shoot for a while, then turn off the station order. They leave after exhausting their bolts, but later on, if they have nothing to do and have not been stationed anywhere else, they return to the chamber of their own volition and shoot at the FB some more. I picture it like soldiers or cops going to the shooting range for practice. The basic principle, as far as I can tell, is that military dwarves with nothing else to do may return to the last place where they were stationed and saw combat.

Seen it in many previous versions, military will go to the last place you ordered them to go to on their off hours. I got in the habit of always ordering them home after an engagement.

Yeah, that sounds like a good idea.
Don't want them to wander around in case I need to evacuate the outside area.

After a military encounter, I usually order all the military through the auxilliary baths, to clean them off a bit. Blood, floating eye ichor, and so on washes down the drain. I have noticed since that the military often seem to go and walk through the baths on their off time. I had figured till now that I was just noticing them more often, now I wonder if I've given them OCD.... I probably should check.

I'd not report this as a bug. It's definitely a useable feature.

Yeah, definitely a neat feature.

If you don't have any meeting place, a dwarf on break will go to where he tried to path to in his last job.

Yep, pretty sure I've noticed on break miners returning to places they've mined (sometimes very hazardous, especially in plumbing!) I didn't know that a meeting place stopped them from doing that. Does just a meeting zone count? A dining room that's not designated a meeting hall? Or a meeting hall itself? Because I feel like with a dining room, I've still had dwarven miners that have been on the job for a long time wandering about their workplaces instead of going to the dining room for their "no job" or "on break" time.

This might relate to how some ghosts haunt the places they visited in life. I don't doubt that the game keeps track of it, and that it's related to jobs.

Of course, it might vanish a little bit in the next update with the removal of generic breaks. Or maybe antisocial atheists will exclusively go to their rooms / recent work areas. That would be cool, crabby old dwarf hanging around his mason's workshop developing grudges against passing kids

How to Weaponize this...
USE #1: Set up Presser plates on said site and have them Linked to Torture chamber/the place you keep your beasts for the arena (to keep them on there toes) ect. and it will be delivered at random times causing anything from the floor falling away to Spiketraps or anything else you can imagine.
USE #2: Set it up as an Auto feeding system for your dwarven day care!!!