There is no benefit to packing as much as possible into a line of code. Separate it out as much as possible, make it easy to read.
Strictly speaking, there is no need to call join() in this instance. The purpose of join is to make one thread wait for another thread to finish, but it’s a pretty crude form of checkpointing. Since the JVM will exit anyway when your started thread ends and this is the desired behavior, you don’t need to explicitly call it.