I see the distinction, but they have both been going on a long time.
Constant contemporary cannibalisation aside (**3-hit alliteration counter-combo - 1000 points**), loads of old hardcore was made into early underground garage, (We R E, Madie in 2 Minutes, Hurt U So etc etc), then loads of 2-step re-hashed all the early garage (I have four 2-step versions/boots of 24hr experience's 'Together' for example), the late 90s saw loads of UKG producers re-defining each other's earlier work (see the 4 trillion remixes of 'I Refuse' by Somore Locked On released for example) as well as looking back to Jungle/D&B/Hardcore/everything else.
Then loads of UKG/2 step tunes were VIP'ed into new grimier versions when grime started to happen, e.g. Bump & Flex's mix of 'All I Do', Saved Soul etc. These records were released in a matter of months from the originals, but already they were being put in a slightly different context, harping back to a different sound and in fact creating daylight between the two. Even that rub of Dilemma that Slimzee used to play so much could be seen this way, as the original So Solid joint was arguably from a different 'era' in terms of UK garage.