I have been very impressed with the Meta Box team and their continual improvement and expansion of the product. A block to add an MB View in the Gutenberg editor makes sense, but there is also a MB Blocks extension and I understand that the intention is to also bring a similar Twig and editor experience to that MB Blocks extension.

The Meta Box and ACF block builders make me think that it would possible to allow for core to support PHP based blocks, so that people would not need to learn React.