I'm no electrical engineer, but what I get from that paper seems true enough--that any preamp or recorder that has transformerless inputs and 48-Volt phantom powering likely uses coupling capacitors to block the DC from entering the preamp's input stage. The value of those capacitors has to be high enough for them to pass low audio frequencies.
Thus when 48 Volts DC is steadily applied to them (case in point: if no microphone is connected), those capacitors can take on enough charge to do some damage if it were suddenly all dumped into unprotected circuitry. The 6.8 kOhm phantom supply resistors aren't positioned to limit that current. The microphone's output circuit might or might not have effective protection for such a case. The cable will help a little--mainly, its capacitance would soften the leading edge of the current rush.
So visualize the moment when a TRS plug is halfway into a TRS socket. The plug's tip is touching the ring contact of the socket, and the plug's ring is touching the sleeve (ground) contact. If phantom powering has been on already, and those capacitors exist and are all charged up, then I think that the microphone's output transistors will receive the full charge from the capacitor on the ring-contact side of the preamp--across them, and not in common mode the way phantom powering is designed to work.
I think the author is right: I don't want that. It's not really a different risk from what I was talking about before, but the risk of damage is greater because the current is coming from those capacitors at the full 48 Volts and very low impedance, rather than 30-something Volts via 6.8 kOhms.
--best regards
P.S.: The two messages above mine have both quoted a message of mine at some length. This is rarely necessary in a threaded discussion board--and since there's a mistake in what I wrote, if I correct it now, it will remain wrong in the quotebacks.
Could people please quote back only what's really necessary to show what they're replying to? For my messages, at least? (I very often post messages and tinker with their text later. Bad habit, I know ...)