They will gladly use something like this (many have already started experimenting with other similar products) to get them even 60% of the way there and then they can polish the rest in code...
Which is basically how they used Figma before. Visualize to close enough and then iterate to final in code.
If Claude Design can ingest your design system and previous examples and go further than templates and scaffolding, if it can help you brainstorm ideas and variations so you can - as the human in the loop - get to your final design faster..
Why wouldn't you do that?