I don't think you are missing anything, I am not aware of anything that would automatically launch new threads when evaluating something.
That does seem like an interesting, although in practice I rarely have to evaluate something that would take more than a a couple of seconds, so manually wrapping it in a future seems acceptable.
On a semi-related note, sometimes I mistakenly evaluate something that will take a long time, or there's a bug and I'm stuck in an infinite loop. CIDER has a command to interrupt the on-going evaluation but I'm my experience it only works about half the time. In those cases having it wrapped in a future would certainly be helpful.
That does seem like an interesting, although in practice I rarely have to evaluate something that would take more than a a couple of seconds, so manually wrapping it in a future seems acceptable.
On a semi-related note, sometimes I mistakenly evaluate something that will take a long time, or there's a bug and I'm stuck in an infinite loop. CIDER has a command to interrupt the on-going evaluation but I'm my experience it only works about half the time. In those cases having it wrapped in a future would certainly be helpful.