Not really true. Joss wrote the first issue of season nine, and co-wrote the second issue. It is true that he hasn't probably been hands on as he was last season, that doesn't mean that he hasn't still be working with him while working with Marvel Studios. We know the man has a lot on his plate and he's kind of always been this way.
He didn't co-write the second issue, he only wrote the first one, and apparently he was closely involved with the writing of the "pregnancy"/abortion arc, though he isn't credited as a writer so I'm guessing he was just telling Andrew what he wanted it to be like. It seems that his involvement in the Buffy
title now consists of Chambliss talking to him about the upcoming issues - Chambliss has said he's been talking to Joss about the ending arc of the season - but I don't know if he's involved in Angel & Faith, the Spike
mini or the Willow