No, fans of their music (like me) will not be turned off by the political concept. It's not as if this is something new, their 21 Century Breakdown album was political, and the band's smash hit, American Idiot was incredibly political. Even though some fans ( like me again) disagree with their politics, I think the music matters more then any political message.
No, it is unlikely that Green Day-fans will be upset about the politics, at least not enough to reject the music outright. Most people are not politically engaged enough to let such issues dictate purchases, as long as they like the product. Bear in mind that there was a major campaign to smear rock band Kiss as being Nazi supporters in their heyday, which despite the efforts did very little to detract from record sales.
Most Green Day fans are ok with the band's politics. They have sort of evolved into a band that addresses social and political issues. Most fans are ok with that. If not, they won't buy their music. Generally if you are socially and politically in line with Green Day, you're probably a fan and will buy their stuff.
Bob Marley used to be a leading Reggae musician. Reason for his success? Political thrills. And politics, rather than love affairs and gangster rivalry, is sure more likely to persuade even those that do not subscribe to the idea of punk rock to buy and listen.
Take for example the song "Bang Bang" in the CD, which is a clear reference to the intractable gun violence in the U.S. these days. Not only fans, but many of us are looking forward to listen to it.
Green Day fans will probably enjoy the band's new CD. Most fans will not likely be turned off by any political concepts. Green Day has long been a supporter of progressive political causes; which many of the band's fans share these same views. Therefore, fans will probably be supportive of these political concepts.