[bostik]

Not quite. It says this "may be altruistic". "May" does a lot of heavy lifting there.

From an outsider's perspective, a more likely explanation is that the funding is a subsidy. The VC having a stake in this space would have invested in a lot of other companies too. If their funding for Flashbots is notably less than the aggregate expected value of their total investment in the ecosystem at large, and if without Flashbots that expected value would drop by more than the funding amount, then the subsidy would be a net positive investment for that VC.

In other words, they may have seen Flashbots as an ongoing cost of doing business.

And if they had indeed achieved staying centralisation, there's always the access fee structure to hike up.