Bob, Gordon, and Luis
I saw the posts here about some of the cast members leaving and fond this article, http://www.nytimes.com/2016/07/29/arts/television/three-longtime-sesame-street-cast-members-are-let-go.html?_r=0, which I think clarifies the situation somewhat.
Before we all panic, the article says Bob, Gordon, and Luis may still appear sometimes, but they aren't on contract anymore. In other words, what i'm getting from that is that it's no longer a guaranteed regular gig, but they aren't banished permanently .They aren't going to be "regulars" anymore, but may be invited to appear on occasion. In addition, it sounds like they've already recorded material for the upcoming season. Honestly, my understanding is that the human cast have been appearing less and less frequently for several years, so it may not make that much of a difference in their daily lives.
This entire HBO saga leaves me with mixed feelings, and I sincerely hope this isn't the first indication of a painful ending for the show. (Granted some would say that's been happening for twenty years already, but this is a whole new level of potential problems.) I'd rather Sesame Street go gracefully than drag things out. At the least, I feel better to know that these guys haven't necessarily been thrown on the garbage heap. There's still the potential for "guest" appearances.
Om Shanti