TL;DR you are probably fine.
To expand on @Batman 's answer...
Let's follow the compatibility back to front:
- Rear derailleur and cassette are designed to work together. These need to match. This should be obvious.
- Cassette will then dictate chain size.
- It helps to mention Leonard Zinn's great explanation about chain "width"
Chain width, as defined by standard methods of measuring chains, is 3/32-inch on all bicycle derailleur chains. But this is NOT the “width” people are talking about when they say, “an 11-speed chain is narrower than a 10-speed (or 9-speed or 8-speed, etc.) chain.” Yes, chains have gotten narrower as the number of rear cogs has increased in bicycle drivetrains, BUT it is only the outside width dimension that has decreased, and really, we are actually describing the length of the roller pins, which is shorter on 11-speed chains than on 10-speed chains.
When we’re discussing differences in width of differing-speed chains, we should call this dimension (the length of the roller pins) something like “outer chain width” or “chain outer width.”
TL;DR cassette will dictate outer chain width. Inner chain width is 3/32.
Individual chainrings only care about inner chain width which is a constant 3/32. If you were running a 1x setup you could use any chainring with any chain (excluding track/BMX 1/8 in. chainrings)
As @Carel pointed out, the front shifting is really crude. The lifters on the chainring are all designed to accept the same chain plate profile. At worse you'd have som stress concentrations. For example, the "narrow" lifters on an 12 speed chainring, lifting a "wider" plate of an 8 speed chain. At worse, this would result in chain/chainrings wearing out sooner (for shifting not for drive power)
The space between the chainrings does care about outer chain width. If the outer chain width is too narrow, it will fall off the inner chainring before engaging with the lifters on the outer chainring. Most chainring spacing is 5 mm, but I don't know of this being an exact specification. I have heard of a few 6 and 7 mm spaced cranks. The narrowest chain on the market now is 4.9mm wide - Campagnolo Ekar. While that chain is designed for a 1x Ekar setup, it highlights the possibility of a chain being too narrow for a chainring set.
- None of this conversation involves shifter <----> derailleur compatibility. That's a separate can of worms
- Obviously we are talking strictly about index shifting. Friction shifting gives you endless possibility for mix and match (separate conversation).