There's nothing to stop the employees from distributing it at that point and even with copyright it gets distributed anyway, it's just not allowed to be used for anything serious.

Which seems very much align with what has Microsoft been trying to do for decades now.

It would be quite impressive if this was a long-time planned "Embrace, extend, extinguish" move against Copyleft, with a casual acquisition of Github to make it work.

Finally, it beat the "cancer that attaches itself in an intellectual property sense to everything it touches" after all those years, with its own tools!

Now it's safe to touch.

Interesting idea considering Microsofts copyright-dependence has reached an all-time low point since they move as much as they can into their SaaS and PaaS offerings. Nothing left to copy, except for employees, but you don't need copyright to bash their heads in, legally speaking.