I would not make an analogy with Redis (I don't think it makes sense to offer "managed uv" as a Saas), but perhaps with Docker/Conda, i.e. buy a license if you are a company with more than X employees/YM revenue.
Nevertheless, I think it's not the best choice. They'd better build another SaaS (à la Vercel) or add paid features (like Docker Scout). They would only lose a huge market share if they restricted access to uv, and it's their medium to make money.