I've read a lot of false stuff and misconceptions here so I feel compelled to answer.
First, I don't know why people are so 'scared' and concerned about that Allegiance licence.
Reading stuff like 'They can shut us down anytime' reminded me of kids in a classroom...no they can't but more importantly they don't care at all.
Like TE pointed out the licence is MSR-SSLA (shared source). Don't be paranoid and think M$ is evil in everything they do.
They put this licence because it's the one they use with everything released by MSR (not MS). Not because they had an evil plan for Allegiance...
Do they care about what we make with that 10 years old buggy source code ? not at all. they might eventually care about the trademark 'Allegiance' and other names like Gigacorp, Iron Coalition, Bios, etc. So be advised that some negotiations about these trademarks (and these trademarks only not the code) might take place with MS in a near future...
What they don't want is people earning money by using their name as a selling point.
If someone rewrite a 100% identical Allegiance from scratch and call it Pigs In Space and sell it, they won't mind.
If someone compile the code, rename it Pigs in Space and sell it, they can mind (and have the right to).
if someone rewrite 100% or compile current code and sell it as 'Allegiance' using MS brand to attract customers : they'll mind strongly.
That's what the MS-SSLA is all about. They don't wont people making profit by using MS work and notoriety. And it's profit by selling software only.You can charge for hosting a lobby or a game server without violating the licence.
As for the 'granted back' part of the licence (section 5), don't worry either, they're just protecting themselves to not be accountable in case they redistribute your modifications. But this mainly concerned other works released by MSR.
Because, now get real, all the changes done by this community since MSR released the source have no value for MS. Compared to a modern game budget, this is roughly the daily coffee break budget. If they want to reboot the franchise, they'll throw the $ and tons of devs. It's MS ffs, they talk in billions. It's not a random indie 3 guys game studio.
Relativise this: Having one of their lawyers or employees taking time
looking at us will cost them more than what Allegiance is worth today...
As for this 'shared' licence, it stops to "shared". So things like ASGS , CSS, ICE, AME, etc are not covered by it. They are additions not modifications.
Now back to the OP and the FOSS community:
I don't think it's the good people and approach. In fact you might want to keep these people away or the drama we've been experiencing here will look like nothing compared to the one they people can pull out...
I mean as new players of course, nothing bad in trying to attract new devs from the FOSS community.