some miners lost the latest mined coins. some transactions will be reversed. that's it.
BTC is now quite centralized. A small team with guns can hijack the whole network by forcing mining pool operators to co-operate with them.
And who will force the miners to stay in the highjacked pools?
Plus even in that senario what could the highjacker do? They can't tranfer coins they don't control the wallet to.
All they could do is not confirm transactions and slow the network down, people's coins would still be safe. After miners moved to new pools, the network rate would bounce back up.