This is only speculation on my end - but I suspect it does come up in the day to day work of the JUCE team (as they have to work with those cpp files often).
Since if you have Xcode/CLion/VS ReShaper you could get your setup to a point where those CPPs do look mostly correct (perhaps with slow auto complete/false positives once in a while), I think they’ve gotten used to living with those flaws, but would probably be a bit more reluctant to work on the parts of the code that may show that problem even with those IDEs.
In the past, I’ve worked on all kinds of projects that had similar configuration problems in some parts of the code, and the team’s productivity/enthusiasm was definitely much lower when it came down to new features/bug fixes in them compared to other parts/projects that did not suffer from it.