What's that got to do with it?
It's been the same for a very very long time
Actually, you just proved what I said. Here's a closer look at how that border line actually works:
As you can see - the border lane runs BESIDE the road, giving everything on that section of Moggill Rd a street address of Chapel Hill (including Baskins, represented here by a black dot). Everything behind the line is Indooroopilly. If it were on suburb on each side of the road, it would look like this instead: