This is a nice and more technically accurate definition but i don’t believe it’s at all found in the wild, which mitigates its usefulness. I think the bound in the common usage is in the sense of destination rather than limit, ie, bound for an i/o subsystem whether under local control or not. This then implies the local actor entering the ‘blocked’ state that you mention, during which time the local actor is free in principle to do something else.

In short I think I/O bound is a concise way of saying that this work will leave my concern and will pass back into it at some later time.