I highly doubt that Rick will force him out of the 24 for Chase, especially considering Jeff put Hendrick on the map. Jeff is probably the greatest driver of all time when you get right down to it. Most wins by far in the modern era, highest winning % of any driver in modern era, 20+ year career, multiple crew chiefs, cars etc.. coming from someone who hated him for most of my life, you got to realize that he is simply great. I find it hard to believe that Chase will be better than him, even at Jeff's current preformance. Plus, many forget he's only in his mid 40s, heck Dale Earnhardt fought for championship into his late 40s... I would be very surprised if he quits in the next 2-3 years.
That being said, I think that the quicker they get Elliot in cup the better, so who knows... Not sure how long Kahnes contract is for, and JJ or Jr will never be forced out or leave. It wouldn't surprise me if Kaseys the next one to go or not but, I don't see Jeff retiring any time soon.