What might these new, as-yet unannounced, CPUs offer you personally over your current cpu (or 8700k)? You say you primarily game, personally I don't think there will be any major advantage to having loads of threads as far as gaming goes for a few years yet, if ever. Lots of gaming development is driven primarily by consoles and despite their CPUs having more hardware threads (8 iirc), the reality is they are massively underpowered.
You've sat on your current platform for 6 years, if you're that worried and the current rig is still doing ok then you can keep waiting. I was on a 4G 980x for 7 years and switched to an 8700k, which was definitely overdue. I was eyeing up 4790k originally, then sat through skylake and kabylake as I never got around to it. 8700k was a no-brainer, basically it's the same as my old 980x except IPC is probably up 50%, clock speed (stock!) is up 10-20%, power usage is down 50%, temps down about 10 deg, and I paid less for mobo/cpu/ram/block than i did for the 980x alone 7 years ago. To be honest I'm more excited about the power and temp reductions than anything else lol. I expect I'll be sat on this platform for another 5 years.