The person who created those CG is using this patch as a base and filling the gaps with their imagination. Now, what does that patch actually depict? Could it be a UCAV?
It's impossible to tell, even with danielchin's translation. It could be UCAV or a generic picture.
If the number of H-6 bombers built provides any indication I suspect at least 80-120 units. That is if the design proves to be capable.
I was personally rather surprised at Xian's build rates for both the Y-20 and the H-6K so I wouldn't expect this to be a boutique design like the B2.
Also, consider that China also uses the H-6 as an air refueling platform. If they follow this trend with the H-20 the number of units built might be much higher than that. How would you refuel the J-20s for a strike package aimed at the second island chain for example?
Are you suggesting a stealth tanker? I suppose that might work, but it would expose the H-20 RCS value prematurely. Use it often enough and someone will figure it out. I doubt the PLAAF would risk it. However, I'm expecting a Y-20 tanker variant.