The upcoming Samsung Galaxy S20 Fan Edition will reportedly use the Galaxy S20's 12MP Sony IMX555 image sensor. It was suggested earlier that the device would come with Samsung's in-house 50MP ISOCELL GN1 sensor. The last-minute change could likely have been implemented as a cost-cutting measure.
https://www.notebookcheck.net/Leak-suggests-that-the-Galaxy-S20-Fan-Edition-will-come-with-a-12MP-IMX555-sensor.483130.0.html