Well yea isnt' it obvious?... it's working right now even when the mempool is empty because there is still a block subsidy
1. Using drivechains is optional though. People who don't trust it can compl...
drivechain is happening in about a month and a half from now. it's just implemented to cause a chain split. core could copy and paste it later, or do covenants instead just to be different. I think you can accomplish merge-mined sidechains using covenants instead of hashrate escrows and some of their properties will be different/better