Well ignore what people have told you, I'll tell you what I actually know for a fact. I have played 40K since 1990 (Rogue Trader), 2nd edition was my 'expansion edition' where I got into the game, and I've played Necromunda and SWA.

Necromunda is 2Ed 40K with a few extra details for casualties, pinning, beefed up rules. SWA is a near carbon copy of Necromunda rules with the exception that the factions are different and the missions/campaigns are different.

8th is shaping up to be so different from anything we have seen before and whilst there are 2ed-esque elements it cant really be said to be based on.