Well, it seems the rush of new full-frame systems just keeps going, with Panasonic now rumoured to announce their own in September. Knowing them, it will be strongly video oriented though, frankly, I don't think they have the weight or the brand name recognition to push a system by themselves.
Source: https://www.43rumors.com/ft5-panasonic-will-announce-its-first-full-frame-system-camera-on-september-25/
Source: https://www.43rumors.com/ft5-panasonic-will-announce-its-first-full-frame-system-camera-on-september-25/