Take a look at this article.

Just watched this video where they're making some quite interesting claims about server 2016. channel9.msdn.com/Events/Ignite/2015/FND1551
I think it's a ploy to retain (or at least not lose) market share by luring people into their cloud platform, Azure.
Having said that, I'm quite tempted to try it out !!
From a business perspective, it's a brilliant move. SQL Server is one of M$'s most expensive software products. My office spends over $100k per year on SQL Server alone. Compare that to a relatively inexpensive Windows Server license that costs a few thousand. It makes sense to sacrifice a small payday for a large one.
Mario Giambanco
Director of User Experience Development
Neutral
As with any system, there are fans of MSSQL - bringing MSSQL to linux might allow companies to move to Linux from Windows that otherwise were tied to Windows servers because of MSSQL. Even though "most" sql servers try to be compliant with sql standards, each one always has it's nuances.
I don't think anyone that's already on MySQL or Oracle or etc... would move to MSSQL for Linux if they already haven't moved to Windows server; but it might interest new projects / migration projects.
'bout time really; but what direction does Windows Server take now that MSSQL isn't tied to it? It'll be interesting to see what else comes out of this new Microsoft.