My guess would be that they felt no need to update the labels on these pre-release discs to use the HMV name. Albert Coates became the LSO's chief conductor in 1919, and a Google Groups user has uploaded a recording of him conducting the orchestra (well, a part of it anyway...) in Till Eugenspiegel, dating the recording session as November 4th, 1921:
https://groups.google.com/g/rec.musi...MRZYaIUJ?pli=1
Paul