I can guarantee you that the system that's described in the paper is what we use at production. The blog post that you are pointing to was meant to describe the usage of monorepo at Uber and the challenges we faced at a high level. It didn't dive deep into the submission system and we have the paper to address that :-).
(I'm one of the authors as well as the tech-lead of the system.)
(I'm one of the authors as well as the tech-lead of the system.)