Not sure how lean do they run their stuff - I'd assume at least lean-ish, considering they have (had?) a lot of good engineering talent working on it. Asking for a large reduction while at the same time culling staff seems like wishful thinking.
I went to visit a team at Twitter that seemed to have very little to do with their core business. They'd bought some company that my company was using (can't even remember, Fabric or some crash profiling thing?) and I got invited to see their fancy building on Market Street.
But my sense was there were many peripheral teams that your average Twitter user would never notice if Twitter were to cut them.