Originally Posted by TFCash

As long as your not using GA to track stats, they shouldn't have a direct knowledge that they are both owned by you. But, I'm sure they have the same history info as any one else, so if before implementing cloudflare, you had them on the same IP, then you should assume that they know that they are still owned by the same owner. The only way to break that, would be to add newly reg domains directly to CF, then there is no chain of ownership that can be tracked back to each other.