Currently, of course. Travis used to be free for oss-projects too.
I suspect Microsoft is less interested in making a profit on every single part of the github ecosystem, and less likely to change the pricing/limits for actions. But of course only time will tell.
They probably don't care about one person doing this, but if tens of thousands of repositories start doing this it becomes a problem.
> They run all of Azure, after all.
They get paid for that.