If a block of say 2 resistors with one end connected to net 0V are selected (just the resistors no connections) and then duplicated and "all no" selected on the dialog box. Then the resistor copies will still remember that one end was connected and get attached to the same (new) net although they have no connecting wires. This is inconsistent with the behaviour if a connection is deleted from a component where the net info is also deleted (the correct behaviour)
Generally I think a component terminal with no connection should not be connected to ANY net. I have had several difficult to find errors introduced by this strange behaviour.
But if you selected several interconnected components and used 'All No', you'd still expect the interconnections to be preserved, but with new net names.
I would still prefer "All No" and "No" to produce disconnected components (no nets). It's easier to explicitly connect them than search for unintentionally merged nets later. How about a redesigned popup dialog with a tick box to "preserve connectivity"?
I have also noticed that when copy and paste a part of a circuit, components with some 'gates' outside the selected area are missing these gates when pasted. This does not produce any errors. It needs the multigate components to replaced. I add (NOT duplicate) a new complete version of the part and link it in parallel with each gate of the old part and then delete the old part.