Reportedly, a document leaked in Japan indicating that a new small Panasonic Lumix DC-S5 mirrorless camera will be announced soon. The S5 is expected to be a smaller version of the current S1 model. There was no mention of a new GH6 camera. The document was later removed:
It's a shooting grip manual, but it seems that Pana's mistakenly made a public release of a document containing unpublished information. There was an unpublished LUMIX S series model number for the shooting grip model. Clearly stated as "DC-S5".
Via Nomadly (translated)