According to this source, the cancellation is reportedly due to "exhaustion" on the part of co-vocalist Tim Armstrong.
The band's manager, Eric Hellman said:
Tim needs to get better. When push comes to shove, the music is great, and it's a priority, but everyone's health and family comes first. And Tim wants the same things as those guys, but he can't do it in the condition he's in right now, As far as I'm concerned, Tim will always be a member of Transplants. But we're in a position right now where we don't want to lie to our friends. And the honest truth right now is that Tim isn't feeling well right now, and he needs to get better.
The band plans to release the second single from the record, "Crash and Burn" shortly.