Most likely scenario for this is that the blockchain gets rolled back, any transactions after the fork will just disappear, everybody's wallet will look like it did immediately before the fork.

Of course, the BTC blockchain will not be rolled back, so those sides of transactions will remain intact.

Looks like a very clever scam utilising the low network hashrate against the coin because there is so little reward for miners,

You can expect this to happen again unless net hash is increased a lot.

Also, don't like the use of the word "if" in the dev's post......