Without internal Twitter context, but having seen companies with marketing teams... there's a lot of people involved in doing close work with partners, whether advertisement ones or others. On the tech side it's kind of like AWS support - sure, everyone had access to the support portal, but once you start spending $$$, you'll get dedicated people sitting in your company's slack channel, providing support, advice and planning if you need it. (Sure, it doesn't always work great, but the idea holds)