I'm not convinced. The authors cite sources of complexity that are mostly domain-specific artifacts of web development, yet make pretty broad claims about a fundamental advancement in language design. Maybe the authors have some insight about these pain points, but it certainly doesn't seem necessary to create a whole new language to solve them, especially as frameworks such as gRPC have already (at least partially) solved one of these supposed fundamental issues without replacing the base programming language.
I am not convinced either. Getting a language off the ground is a 10 year affair, don't think its possible for a funded company to bring up a new language unless they are targeting some niche where full scale programmability is not a requirement.
It might just transpile into something else, doesn’t necessarily need to be completely from scratch. Their documentation is pretty opaque though as others have mentioned so who knows.