It is no longer a rumor; the next edition, which is the eight edition of the game of throne, will be released in April 2019. When the last edition, which is the seventh edition, ended in July 2017, many people had thought that the next edition would take place immediately. Many people had predicted that it would be released in the year 2018. Now a promo about the next episode has indicated that it will be released in April.
Although there are speculation that this might be the final edition of that game. It is not yet certain whether the next edition is going to be the last edition.