yes, but most intelligent dc-dc psu's use that connections as a 'sense' circuit to tell if the pc is running, or has turned off yet or not.
by keeping it connected all the time, the psu thinks that the pc is always running, so it won't send a startup signal, or will keep trying to power off, but never actually turn off because it thinks the pc is still running..
Mine works just fine with these permanently connected and sends the approriate power on/off signals via J8/J9 as expected. Without the connection, the PSU does nothing at all.
The thing is, with the green and black connected together, the PSU is on all the time. Sure the PC will probably power on and off correctly in most situations but the fact is the PSU is still on when the PC is off unless the M2's time limit has been reached for the hard off. Not a very elegant way to go imo.