That’s the question I have. Even if the bank honestly thought that the house was to be foreclosed upon, the possessions would then be auctioned off to help pay off what might be still owed on the mortgage.
It takes time to put things up for auctions, because you have to catalogued everything, unless you sell it en masse, but even that takes time.
The stuff should have been secured.
The only thing I can think of is that whoever emptied the house might have bought it off the bank unseen, with the expectation of selling the possessions in part would allow for a profit.
The bank has a title to your house (supposing a legit foreclosure) but they have no title to your stuff.
I doubt it. AFAIK, the house mortgage is legally secured by the house, not whatever possessions of yours they can find lying around. They can't repo your car or come to your office and take your briefcase or your shoes. Whatever shortfall might exist after a repo and sale they'd have to sue you for. Landlords can sell your stuff if they lock you out for non-payment, but I don't believe that applies to mortgage holders.