From the first impressions of WandaVision, fans shouldn't expect much action at all from the series until the climax. Marvel Studios is very dedicated to replicating the tone and feel of several eras of sitcoms, which includes the lack of any actual action as they focus on character dynamics and humor. Fans should expect some big action towards the end, as director Matt Shakman has said WandaVision will have “the biggest set pieces [the studio's] ever done.”
A new TV spot for WandaVision has been shown with a few new scenes added, along with old ones expanded a bit more. For instance, Kathryn Hahn's Agnes is pleading if Vision is in Westview to save them all and a brand-new scene showing Wanda wearing modern attire while displaying her powers flickers by:
WHAT THIS MEANS
It is uncertain what Wanda is wearing in this new scene, but it looks a bit like her wardrobe from Avengers: Age of Ultron or something Elizabeth Olsen was seen wearing in December 2019 during filming.
However, that outfit Olsen is wearing on set doesn't seem to button or zip up, which the one in this new TV spot seems to do. It could be an article of clothing completely unrelated to either, but it certainly looks modern and unrelated to any of the sitcom settings.
As for the scene itself, it could be multiple possibilities, such as Wanda attacking a S.W.O.R.D. facility to get the remains of Vision back or a flashback sequence to before Wanda was stuck in these sitcom realities.
Whatever the case, fans are sure to have a lot of action-packed into the last hours of WandaVision with Wanda and Vision going wild with their powers.