Looks like you got your answer several times, but here's a reply anyway. Back in the Phantom 1 days, I did that. I was thinking they worked like the old NiCads. Nope. I killed it. But back then, I dug through the instructions and found no warnings about doing that, so I emailed DJI, explained it all, and they actually sent me a replacement. I think it's now part of the instructions, though.
I have similar batteries for some power tools. One of my drills is Bluetooth-equipped. I left the battery attached and the little blue light stayed on. That was enough to drain the battery to zero, and kill it. The company did NOT replace that one for me.