At an in-person pre-event, Huawei teased that the P40 series would usher in a "new generation of zoom capabilities." While it was coy about what that meant, leaks from Evan Blass and others have hinted at a camera array on the P40 Pro that could make even the Galaxy S20 Ultra seem a bit modest. It's expected to have a physically larger main sensor than the already gargantuan unit of the S20 Ultra, but its use of "just" a 52-megapixel resolution could give it noticeably better low light performance than Samsung's 108MP sensor. Also, apparent press image renders point to an "18-240" lens system, suggesting you'd get 13X optical zoom instead of the 10X from the P30 Pro. Combine that with digital cropping on the sensor and you may get sharp images at extreme distances.
The P40 family's problem, as you might guess, is the US decision to blacklist Huawei last May. This will be the first P-series phone to go without Google apps, and that could pose serious challenges in Europe and other regions where services like Gmail and Google Maps are popular. Rumors indicate that Huawei expects a steep drop in phone sales in 2020, and this may be a major reason why -- its tentpole phone range will lose a lot of its appeal outside of China and other countries where Google apps weren't expected.