OKC needs to improve their depth inside especially if they want to be able to match up with the likes of Denver and Minnesota in the playoffs over the next few years. Washington and Richards are both headed into their athletic primes and would just provide OKC with more big bodies to throw at those matchups. Also, crucially, both of these contracts would be coming off the books right when OKC will need to pay Chet and Jalen Williams in 3 years. Poku and Bertans obviously aren't a part of the future in OKC at this point anyway and they have more picks than they know what to do with, especially since they already have their superstar in SGA and look to have a legit supporting cast in their recent draft picks.