It's possible that an increase in traffic is causing more down time. GitHub teams is now free which has certainly brought more people to the site and/or increased how much people use their current account. GitHub has also been adding a lot of new features. Actions, I believe, is out of beta and available to the pubic. Discussions and Codespaces are in beta. All that could also attribute to the outages.
I'd be interested to see if and how much of GitHub has moved to Azure, if any.
I know your question was simply "Is GitHub down more?" but I think an increase in downtime due to an increase in traffic and features is different than simply, GitHub is down more now that MS took over.
Not defending MS in anyway, just adding to the discussion.
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