Should the ban remain, this seems like an easy case for the Mahkamah Konstitusi. In a past petition for review of a censorship law (Law No. 8 of 1992), the court called censorship "behind the spirit of the times." The court decided not to strike the statute down, but said it must be implemented in a manner that respects "democracy and human rights." (MK Decision No. 29 of 2007). For more discussion of this case, see my previous post on Indonesian constitutional law.
Unfortunately, the court doesn't provide much doctrinal rationale behind the decision. As such, it might also be instructive to consider how other countries handle free speech cases. For the moment, I won't discuss U.S. First Amendment law - as today's Supreme Court ruling shows, our unrestrictive interpretation of freedom of speech is something of an outlier in comparative constitutional law. Most countries have adopted a proportionality test to balance freedom of speech against other government policies. While each country has its own variant, Canada's version, the most widespread, can be summarized as follows:
1) The objective of the law must be of sufficient purpose to warrant overriding freedom of speech
2) The means chosen must be reasonable and demonstrably justified:
a) The policy behind the law must have a rational basis;
b) The law must be the least restrictive means possible;
c) There should be a sense of proportion between the objectives and effects of the law.In R. v. Keegstra,  3 S.C.R. 697, the Canadian Supreme Court used this approach to decide that prohibiting hate speech did benefit society more than the marginal value of permitting such speech.
I'll let readers know if this new censorship case ends up in the Mahkamah Konstitusi. I'll be particularly interested in seeing whether the court takes a firmer stand against this type of blatantly political censorship and lays out a clear legal test along the lines of Keegstra.