Spider-Man is not a Marvel studios property.
People keep saying "Marvel got Spider-Man back" when that's not the case.
Sony still owns the movie rights to the Spider-Man films. Sony covers all the production costs and reaps all the profits from any Spider-Man film. Marvel just now has a more hands on consultant role in the Sony films. Also Spidey is allowed to make cameos and appear in Marvel Studios films and Marvel characters might be allowed to appear in Sony films.
But Marvel Studios is NOT making any Spider-Man films so it'd be odd for it to be announced as part of their film slate. That'd likely be a announcement by Sony.