Last month saw the release of the 6th gen Intel. Last week it was 7th gen. Yesterday announced 8rh gen. Today you wonder. Tomorrow will see 9th gen.
What's the rush?
Sure there have been improvements. At the top end. Where you aren't at. At 1080p/60Hz your pc is so far above expectations, there's really nothing it can't handle. Upgrading would only accomplish 1 thing, emptying your bank account.
In order to see any gains, you'd need to have a challenge. If you went for a 4k monitor, or 1440p/144Hz monitor and started challenging your system, them an upgrade to meet that challenge might be justified.
I'm still puttering around on a i7-3770k and gtx970. Nothing I play, work with, use, challenges my pc. I still get 60fps minimums in everything on dual 1080p monitors. A $2k new pc would be pointless as I'll get no gains whatsoever, I'll still be seeing 60fps minimums on my monitors..
I believe you are suffering from 'latest and greatest' fever. You look at your older pc and think it's not good enough because there's been so many advances. There have, but not in areas which count.
So what if CoffeeLake gets 30% better fps? You still get 60. The day you don't is the day that you should consider upgrading, and anything current isn't going to be on the table. You'll be looking at 9th gen, maybe even 10th gen by then.
From where I sit, on my old pc, I'd not mind at all having your pc as that'd be a serious upgrade over what I have. Start your 'rainy day' fund now, cuz one day you'll need it, it just isn't today.