I can understand that a manufacturer eventually stops producing replacement components and can eventually run out of spare parts.

However, the Panasonic Lumix GH4 is still in production, it is still available for sale from genuine suppliers, and has not been discontinued or marked "end of life" by Panasonic.

The Lumix GH4 is still available new from B&H and Adorama, two of the largest genuine authorized camera retailers in the USA.

Both retailers have confirmed by chat that the Lumix GH4 has not been discontinued as of 5-10-18