So you have a living style guide that is being maintained well enough. Fantastic.
Now that the design team has gained headspace to think more strategically about their framework, they realize it's time to change something big, fundamental about the whole thing.
Something used everywhere, like Typography. 😱
It can be costly, but it may be worth the effort if there is a real foundational gap that needs to be filled.
How do we get a larger team (30+ engineers) aligned on what it will require to turn the titanic 20 degrees to the left?
Check out a talk I gave at Hired that breaks down how to achieve such a large transition.
Proceed with caution and do not panic!