The persistence of AMD’s AM4 socket, still slated for life through 2020, means that new CPUs are compatible with older chipsets (provided the motherboard makers update BIOS for detection). It also means that older CPUs (like the reduced
price R5 2600X) are compatible with new motherboards, if you for some reason ended up with that combination. The only real downside, aside from potential cost of the latter option, is that new CPUs on
old motherboards will mean no PCIe Gen4 support. AMD is disabling it in AGESA at launch, and unless a motherboard manufacturers finds the binary switch to flip in AGESA, it’ll be off for good. Realistically, this isn’t all that relevant: Most users will never touch the bandwidth of Gen4 for this round of products (in the future, maybe), and so the loss of running a new CPU on an old motherboard may be outweighed by the cost savings of keeping an already known-good board, provided the VRM is sufficient.