If it was those two girls mentioned in the spoiler I bet the company tried to cover it up because both girls ranked higher than Maho and the companies only care about money. The higher you rank in the election the more cd's bought by your fans for votes.
Possible. Or if it's not them, they are doing this because NGT48 is connected to Niigata tourism industry. It is pretty common for the tourism industry, not only in Japan, but all over the world to cover up crimes to protect tourism business. Whatever of these scenarios is true, the cover up is most certainly related to money. Which is why I say if fans want to help her, they should hurt the management in their wallet, only that will get them to do the right thing and be on her side.