Unable to find why "The CW" is blocked on new Roku O/S TV. Can an IP be whitelisted?

Pi-hole does not support selectively "whitelisting" ips on your network. It provides the same dns service to any ip using it.

But if your TV supports it, what you could do is manually set it to use 8.8.8.8 as its DNS, rather than your Pi-hole's IP.