After some googling, I recently ran bitcoin-qt -zapwallettxes on a 0.15.1 pruned multiwallet node in order to remove a stuck transaction from the transaction list, without fully understanding what I was doing. After running the command and realizing what I'd done, I was surprised to learn

1. The operation succeeded without warning despite the fact I was running a multiwallet configuration
2. The operation succeeded without warning even though I was running a pruned node. Meaning I now had to re-download and verify the full blockchain to get my wallets' transactions back
3. The software made no wallet backups despite the destructive nature of the operation

After some poking around in the code a bit it appears there are safeguards against 1 and 2, but they didn't trigger in this case. Maybe because my pruning and wallet options were being set via bitcoin.conf instead of the command line?