The book can not publish itself, it can be published. "Maybe" looks correct to me, but "probably" is better. When you say "maybe" you mean that it may or may not happen, but "probably" means that something has a high chance of happening. Also, maybe sounds more casual to me. Good luck!

Svetlana answered your question on Maybe and I will take care of "publish" one "Maybe it will publish soon" has a meaning of "It is the subject of the sentence and in future there is a 50/50 chance of the subject to publish." It again is a neuter gender and does not apply to a human. So since 'it' is actually the book who is waiting the publisher to publish and since the publisher isn't a subject we will instead use "to be published" a passive voice of the verb "to publish" and thus we get "It will be published (by a publisher)" and not "It will publish" meaning some non-human is going to do the action which sounds plain weird. Also to me, a personal side note, I'd write Probably before 'to be' "It will probably be published soon."

English Grammar in Use 4th edition. Unit 110 (adverbs) Unit 43 (passive voice) Example from unit 110C - "The concert will probably be cancelled." For your phrase, "It [the statistic] will probably be published soon." With less certainly, "Perhaps/Maybe, it will be published soon."