Repeat customers are the bread and butter for all the major cruise lines. Thus the loyalty perks will never go away. Personally I think Carnival's new perks are pretty weak. They certainly don't reach the level of those provided by Royal Caribbean, Celebrity, Princess, or Norwegian.
I also agree with Mike about the suite perks. Carnival is terrible about it. We normally book suites and Carnival gives me no reason other than more room to book a suite with them.