In my opinion, all core turbo really means all cores at 100%.
How did turbo come into play now?!
Intel, and AMD as well for that matter, only provide you with base clock for base TDP, anything above (or below) that depends on what you run so nobody makes any real claims, they give you single core max boost and that's it, everything else is up to the user.
Since these will have more cores, even if they are e-cores, the base clocks for base TDP will be lower but if you run the same game/app on the same amount of p-cores excluding the e-cores the boost should be the same, if not better, compared to previous models.
That's why I asked you what software you expect 4Ghz on, because every one will boost differently.