The word on Blue Beetle is that "Blue Beetle is the first DCU character, but is not a DCEU film," or that "Blue Beetle is a film set in the DCU, but isn't a DCU film." Honestly, I doubt Warner even really knows, and its status will be determined by its success/lack of it.
TBH, I could see it being both a DCEU and DCU film, as in, everything in the film happens in the same way in both settings, but it's two identical series of events that play out in alternate realities. Similar to Peacemaker - season 1 is in the DCEU, season 2 will be in the DCU, so ipso facto, season 1 must occur in the DCU in some capacity, while season 2 presumably never occurs in the DCEU. And if you're saying that's a tonguetwister and this whole thing is confusiing, then yeah, no shit, Brainiac.
Not that I'm overly invested in either at this point, but I'd prefer a clear break, or otherwise, do something similar to what Disney did with Star Wars - have a clear deliniation as to what's canon and what's Legends.