Dear Microsoft, let's open source Age of Empires II
medium.com
medium.com
Not to mention proprietary tools required for building, pipeline, etc. -- that is, IF they still can locate the source and IF it's even possible to build it other than in the special "build machine" they used to use.
Open sourcing .NET means they get contributions and users who would never touch a closed source core. They also make money from things around .NET and from cross-selling products that tightly integrate with .NET.
They don't currently make any money from AoE2. Being as old as it is, it's not for sale new so when it does change hands, it's used or illegitimate. Open sourcing the engine helps the people who already handed over money but it's not going to draw in any more legitimate sales for the assets (which are usually non-free in something like this).
And there are licensing issues. If they licensed used some audio middleware or video playback stuff (very common in games) they almost certainly don't have a license to redistribute that in source form. That means either paying more or changing it out. Either way that's money they have to spend on this thing that isn't making them any money.
Not to mention there are already things like openage and 0ad which replicate or replace the engine with a ground-up free implementation.
Rather than do any of that that, Microsoft commissioned a new engine (and assets) to release AoE2HD. They're getting a £15 for everybody who wants to play their old game on new operating systems. That's just the way you make money from old games these days.
I mean, have we really learned nothing from tying our multiplayer to GameSpy?
Open source would be best, but I'm sure they want to re-release it on every DRM cloud platform to pop up for the next 20 years. Also, legal, etc.
Which is why I think this is almost certainly not gonna happen.
The only reason they sell it these days at all is because the community figured out how to add additional civilizations, and in a pretty cool move Microsoft actually hired those guys to do it officially and they sold 3+ million copies. So I have some faith on their vision in this arena!