This upcoming restaurant is currently being made, no exact date when it will officially open but can I make this a poke stop even it’s not on the Google map yet?
If the restaurant has not even opened yet, I don’t see how you could convince it has significance to the community and is not just another restaurant.
Edited to add the link to the clarification:
Just to add to @cyndiepooh’s feedback above (I would also not nominate a restaurant that doesn’t yet fulfill its function, and would wait for evidence that it’s a social hub to materialize), being added to Google Maps (not sure if you mean a pin or being visible on satellite or Street View) is not a requirement, nor are pins (which are user contributed) proof of existence or location. This is useful to keep in mind also while reviewing.
It looks a bit generic to me, so unlikely to get accepted.
However, if you submit a wayspot and then immediately log into Wayfarer, you can put the nomination on hold and release it when ready.