the bbc sound relies on excellent drivers in a the lossy cabinet design (over open frame stands) and a slight depression in key treble frequencies to deliver an acoustic orchestral mid hall type of sound, notable for warmth and easy ambience, with very accurate tone and timbre
modern versions representing the bbc heritage take certain liberties and pride of authorship, so to speak, according to their sense of good sound and market demand
these nuanced differences are useful for those interested in harbeths, spendor classics, stirlings, grahams and so on... to my ear there is no doubt harbeths and spendors (sp series and current 'classic' line) slightly smooth and enrich the sound with their own fingerprint, making sharply recorded content come across as more appealing more listenable ... my own spendor sp100 r2’s do this a touch less than the mon 40’s but they both do it (and in quite a beautiful way imo)
this is akin to what good tubed gear have done vs solid state for eons, making our music more organic, more listenable ... whether a particular listener/owner views this as a good or bad thing is taste and system dependent