It sounds illogical to ask for a Bengali sub board for Bengali translation and press release because we don't have any local boards yet. But the way the Bengali board is hammered with translated topics and news source posts, it looks like spamming to many of us. I am not against translating informative topics created by global members with permission, but some members are using it as a loophole to rank up quickly. Every time someone translates a topic their post has been rewarded with 10 to 20 merits. As a native speaker, I can say that very few translators met the translation standard, and most of the translation was done by Google Translator and later edited a little bit and reposted. I can not blame global members for contributing to those topics, as they can not speak the language and have little understanding of it.
There is nothing bad about ranking up but this loophole has been noticed by many new members who are also trying to use the same kind of tactics to attract merit sources, which leads to spamming the board. There are countless informative topics on the global board that can be translated into every local language, but that doesn't mean we need to translate them all at once. Translation should be done when the necessity of that topic arises.
Your statement of "Translation should be done when the necessity of that topic arises" is totally wrong, like, I do agree with you that, many new members or old members try to translate topics even in my community many members try to do that, but I don't think the factor of necessity is worth to be mention here. Because there is no necessity at all but it's an open opportunity.
If you think newcomers are doing wrong work, like using translators to translate the topics into the local language, and if that is against the rules of the OP of the topic, then you can open a case of it, easily. Or you can tell the OP of the topic about it.
Besides all that, the reward that those OPs gave, either of 10 merits or 20, it is obviously not fixed, of course, they will reward you if they would like your work, but overall, you should encourage your local guys, to be creative and be legit too while translating the topics. If they still ignore you, just open a case and leave it to the moderators or DTs of the forum.