It is just like synthpop being a precursor to techno. Synthpop is white music whilst Techno is black music. Radio Babylon is dub, it provides typical dub technique (small room/overreverbed room), and the only thing it can be called 'dnb' for is the combination of percusion with k-s-k-s-.. rhythm, which is hardly an invention of MBM. Four arguments to Radio Babylon opposition are:
MBM is an experimental band. (there has been already noted somewhere that Kraftwerk's 'Radioactivity' was once 'recognized' a first dubstep track by some)
Dub is a genre of vast (Can you definetely state no simillar dubtrack has been written just before /or much before Radio Babylon?)
MBM's track isn't related to Rave, as Dub (or reverb technique) isn't related to Rave
Two years passed till another tracks of jungle have appeared if Radio Babylon is considered a first track.

Arguments in favour are:
MBM are British, so they are connected somehow to British Rave scene.
Track's rhythm is quite a simillarity with jungle music rhythms.

Second argument is like 'drumfunk was created in the times jazz/funk drum improvisations appeared (20s to 60s)'. The first argument is weak without the second one.

One more argument that MBM's track is sampled in some jungle tracks as a straight shortcut to jungle music roots according to creators of those tracks. But it is quite a pov argument.

I don't know the roots of Rave, the scene was dominantly white, and the guy who brought acid house to UK was white too. But who started using 45rpm breakbeat over 4-tofloor is enigma to me personally.

Black music may be considered a 'racial term', therefore i think you'll enjoy more politcorrect one: 'Pop music genre created by black people of African/Carribean (may be also Indian) origin'. I asure, no one here wants it to start any racial war.  82.209.225.33