Vega iGPU is becoming like 14+++ for intel.

Ok even if with 8CU that's better and sligtly faster ( for 100MHz... and if it's like 3400G vs 2400G that's harder to OC, means that's useless) with DDR4 3600 up to 5400MHz/VCN 2.0 DCN 2.0 how can improve performances?
Short calculates... (like every year) WOOOOW +15% XD

With N7P+ they earn +10-15% of space from standard N7 and from 14nm that got 11CU [2400G] they normally can get into APU (at least with bigger improved CUs Vega) 14-15CU.

Higly probably will exist next year R9 5900G, hope that Igor's lab was right that can contain Vega 20 , but it's hard to believe also because is too large for an APU, but not impossible get 15CU with 170-190mm^2 die size

AMD really should focus on getting the essentials right for a laptop, in particular good docking IO such as USB 4.0 (or, at the very least, TB3). Otherwise, no proper 4K@60+ multi-monitor support. That limitation is huge for the market of today's best premium AMD laptops, the Thinkpads.

8 CU's remaining in Cezanne won't impress anyone because AMD is using the same enhanced Vega iGP.
If AMD adds more CU's (such as 10 or more), then yes, it would definitely be faster... but right now, what I think is more likely to happen is that AMD will be focusing on CPU upgrades (IPC uplift, slight frequency increase, more unified core design, etc.)

How exactly could it impress? It still has 8 CUs and the frequency improvements are done. It will be similar to Renoir with better cpu perf.