Evolved so quickly that cars had to start using fake vents in order to make up for the empty space? That or spend money on a new front end and halogen housings just to fix that issue (aka 2017 Jeep Grand Cherokee refresh).

Housing size that the front end was made for.
Housing size the front end wasn’t made for (add plastic).
Front end redesigned for new housing size!

And here is a reminder of what the new Acadia looks like: