Behind the Thrills
has posted what appears to be a lien filed against Seaworld by Bolliger & Mabillard which seems to endorse the theory that a Surf Coaster is on its way at some point:
So far we know B&M have trademarked the name 'Surf Coaster' and that Seaworld Orlando received a shipment of parts labelled 'SF-A' (Surf Coaster 1). So far enthusiasts have been speculating on this being a new stand up coaster (and there was a pretty bad fake 'blueprint' circulating around), but I've always backed the idea that it could be B&M's take on the Blitz Coaster, and the lien mentions that this is a launched coaster.
All these little clues seem to be giving credibility to the idea that we'll be seeing a new B&M product soon, although coronavirus could have the final word I suppose.