Dunn addressed that specifically in his Melvins tour diary, saying:
The Melvins Lite lineup - which includes Dunn - is on the road for another month.
There's nothing worse then some rock'n'roll brat throwing a tantrum and going AWOL just because he can't keep himself occupied. Yes, I'm referring to that little weasel in Green Day. That guy's main problem is that he doesn't realize that he is Justin Bieber. He should take some of the green in his wallet, buy himself a green smoothie and relax. What kind of band name is Green Day anyway? Is that in reference to all the chord progressions they continually recycle? But I digress