They don't have to be the same. Apples and oranges are not the same but they have enough similarities to be comparable in certain cases.

When Twitter's defense against the government's request is because of the ideal of free speech, not the First Amendment but the ideal that it is based on that predates the First Amendment, then it is worth pointing out the double standard in Twitter's own behavior not upholding that ideal.

That said, Twitter having a double standard does not invalidate their argument. From a purely logical perspective, an argument does not depend upon who says it or why they say it. But rarely are people interacting on that purely logical level, and so Twitter's double standard does allow us to both poke fun at Twitter and to call into question their actual reasoning as potentially being different than their stated reasoning.