Fascinating only the culture you put into the city before you gift it seems to be factored in. So you need to have owned the city for 1 turn before gifting it away.
Well you could make a spy in Moscow and get a spy down to the spot at least a few turns earlier than the settler and workers can clear it. That gives you the discount earlier, so if it helps with timing there is that option.
Also we would only need to keep the city 1 turn instead of paying the extra maintenance for 5 turns. Maintenance on that city is... right now in test game city maintenance is 68 and inflation is 44 after settling that city on T164 city maintenance goes up to 76 and inflation to 47. So that city costs us 11 gold per turn.
Edit: but it would produce ~11 gold/science per turn. Runs merchant specialist for 3
& 3
Edit: Doh! can't run merchant specialist must be working the rice! so only produces 5 gold/science from trade routes and 1 commerce for city tile.
The spy could wait before it is settled racking up the espionage discount either way.
Then you could avoid starving (or at least run 1 more specialists than you could otherwise) during a very nice time to run specialists (GA and pacifism). Gives us a GP from Moscow. And 1 scientist in Moscow produces 18 science per turn. Over 5 turns that is 90 science.
Cost is another settler and confu missionary to settle new city for Mao.
one small benefit there is no chance for the spy to be caught in DeG city or in Mao's.
Since we settle it with the spy waiting there already for 4 turns.
Keep the city 1 turn
Next turn gift the city, use the spy to steal the tech at 50% discount for stationary spy
use musketman with guerilla II to raze city that turn.
Make a 2nd settler, confu missionary (~75 hammers/food for Settler since we get a 50% hammer bonus on them and 40 hammers for confu missionary)
So benefit of not growing to 2 pop and instead settling/razing is
1) better timing
2) 90

, 45

in a useful place, + 24

/

(from extra maintenance - commerce produced)
3) no risk of spies getting caught while waiting.
edit: 4) more flexible if we run into difficulties getting Mao down to 3 cities.
Cost is
~115 hammers for 2nd settler and confu missionary.