Huawei has applied for FCC certification for the P Smart (2019) and the papers reveal some of the smartphone's specs. The most important one is the battery capacity - the 3,320mAh cell in the new model marks an increase from the existing P Smart's 3,000mAh capacity.
Going by the less consumer-friendly POT-LX3 name for certification purposes, the phone will exist in no less than 4 versions depending on number of SIMs and amount of internal storage. Single and dual SIM variants will be available and 32GB and 64GB storage options are in the works. In any case, there will be 3GB of RAM on board.
Sifting through the docs (some serious scrolling over pages and pages of test data required), you can also find schematics with the dimensions of the phone - the footprint is 155.2x73.4mm. It appears there's a dual camera on the back, while the single front-facing cam is in a waterdrop-style notch - so unlike the current P Smart+ with its dual selfie camera and 'conventional' notch.
For the rest of the specs we'd need to wait until the official announcement - or at least the next round of leaks.