They've both been missing work lately. It's a passive aggressive move against each other. Word is that Opie loathes Anthony behind the scenes since Anthony was trashing FH Riley's. When they start missing work it's a way to piss off the other. "See how much you can do without me".
I love how O&A spend an entire two weeks boring the listeners with talk about how "Sirius won't send us to the Super Bowl wahh wahhh waaaah!" but then they don't show up to work the day after the Super Bowl to talk about it.
From someone who has been listening for a decade a so, the shows they did without Jimmy over the past weeks have been great...laughing at each other without character overload Norton. There are no issues outside of hating management, stop being a yenta.