I don’t think this is Bo-Katans helmet in the teaser for season 4. Although she WILL be in season 4, this is a helmet of one of her Nite Owls.
Bo-Katans helmet marking is Black.
Her followers markings are White.( same as rebels pic)
Plus, there is no curve in between the “ eyes”.
Cant wait to see her in action once again. Please don’t kill her off.