I didn't think it would be, but I didn't know for sure, and you know what they say about assuming.
Asking on the forum is a whole lot cheaper than screwing up a board and having to order new ones.
The very reason you had put in some optional components is very much a thing. The beauty, as you thought, is that you can design them in, and simply not populate them if you can get away without them. Or maybe they arent needed for a particular version of hardware. Or maybe you want them for a later revision of hardware. Multitude of reasons, none of them bad (except taking up space, which maybe you need if you have a very compact design to achieve). Probably best to design components in and not populate them -
that might save you from having to re-spin your boards!
Heres a couple of pictures of some production boards. The first (green) one came out of some telco gear, lots of unpopulated positions there.
The black one is out of an Apple keyboard. It looks like they gave themselves some options to either populate a MOSFET or a 0 ohm jumper on some kind of power rail, but in this case they seem to have gone for the 0 ohm jumper option.