Technically, only a Profile Manager can make the last name change. Someone on the Trusted List but not as a P.M. cannot access that particular edit. I know, I've tried several times. Always had to wind up enlisting the PM to get-er-done. Kinda makes sense. Wikitree policies pretty much eventually force a PM to add almost anyone to the Trusted List if the requester puts up a fuss with the "Problems With Members" or "Unresponsive Profile Manager" functions. So, restricting the LNAB edit prevents any Tom, Dick, or Harry, that may or may not have valid reasons and/or sources, from making such an important change.