Shawn Levy

Shawn Levy in an interview with Collider. Regarding when filming will wrap.

Shawn Levy:“I have been, along with the brothers, we have been kind of tag-teaming it and directing it as recently as now. So not quite done filming. [We’ll be done] imminently.

Regarding a release date announcement.

Shawn Levy: "All I can say is by the time this airs, we’ll at least have given the world a ballpark. And I’m not allowed to say more. By the time Free Guy comes out, August 13th, part of that answer will be known.”

So it's probably going to be another teaser that will very likely say "Coming early next year" or even something like "Spring 2022", or if it is this year they would say "End of the Year" or give a season or holiday like "Coming this Christmas".

https://collider.com/stranger-things-season-4-release-date-announcement-when/

‘Stranger Things’ Season 4 Announcement Is Coming in the Next 10 Days, Says Shawn LevyCollider