I was under the impression that .1 updates were always stand-alone. But Apple just released what appears to be a Sierra 10.12.1 Combo.

Waddya think, is this a wrong understanding by moi or is this something new?

Whatever it is, it neither looks like a combo nor does it say that it's a combo. In any event, how could it be a combo when it's only updating Sierra by one step? A combo should update several steps at the same time.

Thanks, Jon, for setting the record straight.

Could it be the ravages of time & tide? Nah...

If you interpret "combo" to mean "also includes all updates released prior to this for this major version", and 100% of 0 is still 0, then technically speaking, all .1 updates are combos.