I've been reading about them for years. Rolls-Royce was going to make the engine (the most important and innovative part of the plane), they dropped out in 2022, and then they said they are going to make their own engine. That update you posted is from 2022. Latest update they've posted is from June 2023[0], and they only mention some contractors and that the engine doesn't exist yet. I think the whole thing is vaporware, they'll never make a single flight.

[0] https://boomsupersonic.com/press-release/boom-supersonic-ann...