I pondered and did some limited testing in the scenario.
Please note that while I hold a community volunteer title, I assumed all risk in testing out of my own curiosity knowing I could negatively impact the device using it outside of the standard configuration.
I tested charging the Wyze Video Doorbell Pro with 2 different solar panels.
The Wyze Solar Panel for the Wyze Cam Outdoor and a larger 5v 6w Solar Panel.
The Solar Panels do in fact charge the VDBP and the App recognizes the power source with the lightning bolt icon.
But! Keep in mind that pulling back the silicon cover from the charge port renders the device susceptible to the elements and would most likely void the warranty if leaving the micro USB plugged in to the VDBP supplying power to the batteries in a deployed state. Which is where the primary risk applies in this use case. If willing to take that chance, you would need to perform additional measures to waterproof the connection.
Also think about mounting with the micro usb attached to the VDBP.
What I did not test was any long term affects of leaving the device connected to solar panel. i.e. does the constant charge of the solar panel with little discharge to the batteries installed in the VDBP have a negative impact.
Similar curiosity project I have been working on with the original video doorbell and a similar deployment approach.