Can someone help me understand if this is a big deal?
It's not. It's the reputation damage control, largely superficial.
Why do people here have to be so cynical? Twitter is doing a good thing here arguing that the government saying they can't release NSL number they are restricting free speech, which is completely true.
Releasing these numbers pose no threat to national security and just shows the DOJs scorched earth policy when it comes to defending their perceived powers.
This is a great thing for Twitter to do and it should be praised for doing so, not be given cynical/snarky replies.