The last two weeks that have aired (episodes 3 and 4), John Reardon has not appeared visually at all, with only a brief voice phone call both weeks. This came shortly after the new Rex replaced Diesel who died really early for a dog. :( But at least it isn't a contract dispute or John wanting to leave the show. He announced in December a diagnosis of tonsil cancer, which meant he needed a really reduced role. Fortunately he has recovered and will be returning at some point. epguides.com lists 8 episodes for season 7, which is also a lot less than previous seasons. My guess is episodes 5-8 will continue to have a reduced Charlie and they will film the rest of season 7 when it can be Hudson centric again, or it will just be called season 8. I did like Donovan having more time tonight. But last week Sarah was boring as the de facto human lead, she only works when interacting with Charlie. UP still needs to air seasons 4 and 6.

https://www.yahoo.com/entertainment/hudson-rex-why-fans-think-062115386.html