AMD looks prepared to update each of its mainstream and HEDT CPU lineups annually, and the third gen processors coming next year will most likely need a new chipset, since the red team is making the jump to 10 nm and even 7 nm. The upcoming Threadrippers are rumored to be accompanied by a new X499 chipset, which should bring support for PCIe 4.0 and DDR5.
https://www.notebookcheck.net/AMD-could-announce-X499-HEDT-platform-for-upcoming-Threadripper-CPUs-at-CES-2019.329460.0.html