Honestly once Microsoft takes over GitHub I may migrate my GitLab / BitBucket projects to GitHub. It will not surprise me if they open source GitHub and allow private repositories to be hosted for free. They ran CodePlex for 0 profit. They can make some profit off GitHub but probably can afford not to turn it into a cash cow and thats ok for them to do because their profits will come from elsewhere. GitHub is going to be their way to ultimately give back like never before to all developers on all platforms. Disclaimer I don't work for Microsoft I just don't drink the Koolaid of blind hatred.
Yeah given how much they paid it’s clear they’re not intending to directly profit from Github’s sales. Allowing free private repos seems a logical step