One other case I can think of that H.G. didn't mention (in his own reply to this post of yours) might happen is if the board is not rectangular/square, such as being made possible due to being played on an irregular shaped board (e.g. this could even happen as a possible result of a CV being played where a number of board cell[s] are laid down in alternative turns by each side, before each side's pieces are then alternatively put down, then-completing the setup phase for such a CV). Then, in a bare K vs. bare K situation that may happen much later, one side's K might be able to move to a cell, as if out on a limb, and then a move in reply, by the other side's K, stalemates that K, immediately.
Here's an example of a CV I played a few times decades ago, where irregular board shapes can routinely happen during a setup phase, as I alluded to above:
One other case I can think of that H.G. didn't mention (in his own reply to this post of yours) might happen is if the board is not rectangular/square, such as being made possible due to being played on an irregular shaped board (e.g. this could even happen as a possible result of a CV being played where a number of board cell[s] are laid down in alternative turns by each side, before each side's pieces are then alternatively put down, then-completing the setup phase for such a CV). Then, in a bare K vs. bare K situation that may happen much later, one side's K might be able to move to a cell, as if out on a limb, and then a move in reply, by the other side's K, stalemates that K, immediately.
Here's an example of a CV I played a few times decades ago, where irregular board shapes can routinely happen during a setup phase, as I alluded to above:
https://www.chessvariants.com/rules/choiss