I promise you that my write up did NOT mention that. I have no clue as to the real technical operations behind it... Thanks for the info though.
Many have diplexed it with no problem - yet. When D11 is live, we'll know if they still work at that point
With the SWM8 having OTA diplexing built in, it is resonable to believe that the SWM LNB will work too. Given you have good diplexers (don't cut off any of the bandwith) and of course remember that D* doesn't support it.
That said, I personally don't diplex.