It does look like Philly was lucky to get out of this one, but their fans were talking about a possible Horford for Hield trade over the last month or two, so I guess this is a lot better (for us) than that. The Sixers also won't exactly have cap space...only Danny Green.
One last important piece, Horford is really only guaranteed for $14.5M in 2022. The $26.5M would have been guaranteed if the Sixers won the championship any year during his contract and it would have been $19.5M had they simply made the Finals. I am not sure of the logistics of this contract language after a trade has taken place, but OKC isn't going to the Finals any time soon. If it's only $14.5M in that last year, it is a lot more palatable.