These valuations, as always, need to be taken with a massive grain of salt - if only because sports franchises come up for sale so rarely that they're mostly meaningless as hard numbers. Outside of massive litigation, we'll never see 'the real books'.
Relatively speaking, though, I think it makes sense. Golden State is fleecing the SV herbs for all they're worth with the new stadium, and hasn't seen any fallout from completely pricing out the majority of their fans who would have come to Oracle a decade ago.
Even if that changes a bit as the team cools off, being the owner-operator of a massive venue in an incredibly expensive city is going to boost the team's value immensely, because presumably the sale of the team would include the owner/operator rights to the Chase Center.