I’ve got to think that Rocket Lab’s announcement came earlier than planned because of this announcement by Relativity Space a few days ago:

https://www.cnbc.com/2021/02/25/relativitys-reusable-terran-...

Relativity is claiming to be working on a fully reusable, Methalox burning, competitor to the Falcon 9. Of course Relativity has yet to put something into space so Rocket Lab seems better positioned but these companies are all competing for the same funding and launch contracts so they can’t sit back and let another company steal the lime light for long. Really exciting times in the space industry, the US could have four different companies making reusable rockets in the next 5-10 years.