"What slows down a team where agents do the implementation is the production of specifications precise enough for an agent to pick up and run. Roadmap, written down. Acceptance criteria, written down. The “what we actually want” forced into precision, be it via a test suite, a ticket, or a written design."

This is merely speed of development and not the velocity of a company towards higher value. There are many PMs confidently (using the same AI tools), without a clear deep understanding of the user problems or why the requirements will be adopted by their target users (or even who the target users really are), writing these done elaborately.

So yes this will lead to faster end-end execution. But if the product is used or if it sits unused will depend on things beyond the above.