This is a good decision for 2A. It can be cited in other court cases that even illegal immigrants have 2A rights. Therefore, the government has to work even harder to justify 2A restrictions placed on its citizens, whom, by definition, must have more rights than illegal aliens.
Here's a brief explanation ...
http://stephendpalmer.com/differences-unalienable-civil-rights/
Here's an even briefer one ...
Self-defense is a natural, unalienable right.
The right to vote is a civil right.
Both natural and civil rights are codified in Constitutional Amendments. Natural rights existed, in theory, before they were formalized.