Season 7 devotes a lot of screen time to mentioning and reminding us of Dany's alleged infertility. Jon even asks Dany if Mirri Maz Duur is a reliable source of reproductive advice shortly before paying a visit to her bedchamber.
This seems like a lot of setup for a storyline that never paid off and was never mentioned in the final season.
Drogon disappeared in season 4 and flew away again in the series finale. Could Drogon have found another dragon and made some dragon babies? Could there be an entire population of dragons somewhere off the map? After all, Dany's three eggs had to come from somewhere.
Did Jon desert the Night's Watch to live with the wildlings?
It's unclear from the final scene whether Jon Snow is leaving Castle Black forever or just as a temporary escort to the wildlings. Does the closing gate indicate that he intends to live out his days as the King Beyond the Wall?
The last time we saw Meera was back in season 7 when she left Bran to return home to Greywater Watch where she intended to protect her family from the Night King. Given that the dead were defeated before making it that far, we can assume she's still alive.
We think Meera deserves a little credit for escorting the new king around the frigid north for multiple seasons.