It happens. Sometimes a founder doesn't want to be part of the new organisation and negotiates a quick departure as part of their terms. If all parties are happy it's fine, and not a sign of anything negative.
(not implying that this is what happened here, just adding a scenario where that happens)
Github is way more hyped accross engineers but VMWare is 30 times bigger! VMWare is simply one league above Github.
Github is a Business Departement part of Microsoft. VMWare is a huge company.
This is the typical fallacy of B2C vs B2B. Consumer products are way more hyped and therefore people think they are way bigger than other less famous B2B Enterprise products
Most people with experience in this area would appreciate that one isn't better than the another. They are just different.
Plus, a VP at VMware isn't going to be in charge of that whole $9B like a COO is. Bitnami is going to be a "Business Departement" too.