Infinite cap space for OKC is worthless in regards to free agents. They might be able to take somebody else's bad contracts for picks, otherwise they are screwed.
And you and I definitely have different definitions of perfectly situated for a total rebuild. I'd much rather approach a rebuild the way Boston did than losing valuable pieces for nothing. The worst mistake this franchise has made in my life time was playing for 8th seeds when they should have been proactively rebuilding.
Anyway, if GS wasn't who they are and OKC had a really good chance at a ring, then this gamble would look a whole lot better. If they end up losing everybody for nothing, I'm guessing they'll be filled with a whole lot of regret.