This was the MOST confusing release I've seen in years.

Okay, it took me some time that the mail client is called "ThunderBIRD", not the BOLT. Not that I've used it much. But why the logo in github still shows TunderBIRD?

It looks like Mozilla is trying to catch the band wagon for no particular reason. They don't need it AT ALL. But they just jumped in along for a ride.