Roof & Solar Panels

I know someone who works for a solar company and they currently don't provide roofing in house.

I'd love to set up an ongoing relationship with them where we provide the roofing services.

My question is around the solar panel mounting. If we replace the existing roof and their company comes and then installs solar on top, does this void the warranty (GAF) of the roof?

Is it different by the type of roofing i.e. low slope vs pitched roofing?