It's historically been tough to compare them to Atlassian because Atlassian has provided tons of other enterprise services like Jira and Confluence, and an 8 year lead plus going public, but I think Github is definitely working on better squeezing into the enterprise space with this current announcement.
https://www.quora.com/How-close-is-GitHub-to-returning-to-pr...
https://signalvnoise.com/posts/2486-bootstrapped-profitable-...
http://www.businessinsider.com/github-is-now-worth-2-billion...
It's historically been tough to compare them to Atlassian because Atlassian has provided tons of other enterprise services like Jira and Confluence, and an 8 year lead plus going public, but I think Github is definitely working on better squeezing into the enterprise space with this current announcement.