Failure of an exchange or pool to upgrade to Monero v0.10.1 by January 5th

Question

According to the release notes:

The main thing to know is that you should 0.10.1. Otherwise, you will get booted off the network. If you are mining, make sure the pool you are mining on has upgraded its daemon. Only this version will work after the fork of January 5.

What is the worst case scenario if a pool or exchange does not upgrade in time and is forked off the network?

Would miners be at risk of losing anything other than the block rewards generated on the wrong fork?

Would users of exchanges be at risk of anything more than failed transactions if they send XMR to or from an exchange on the wrong fork? Could exchange users lose XMR?

How can a user of an exchange or mining pool verify that the exchange or mining pool has upgraded to Monero v0.10.1 - Wolfram Warptangent?

Answer 1

Miners will lose what they would have gained if the pool had been on the right fork: any block mined on the wrong fork will eventually get reorganized away. If the pool's on the wrong fork, any money from the wrong chain it sends miners will be just that: on the wrong chain. It will therefore only appear in wallets running the wrong chain. This will hopefully not include the miners themselves, and it will certainly not include ecxhanges.

Users sending to an exchange from the wrong fork will not see any money arrive. But then they won't have lost their money, since it'll still be there in the correct fork, so they'll see their money back once they update. Users can't sent from exchanges on the wrong fork, unless the exchange itself is on the wrong fork, and that's unlikely to happen.

You can't directly check whether a third party has upgraded. Best you can do is ask. Once the chain has its first ringCT tx, you'll quickly see who has updated and who hasn't, but that may be a bit late. There is close to a month to update though, so there should not be any issue, given the update is uncontroversial, and of obvious benefit to everyone.