Intel have recently announced that there could be a shortage of there CPU’s for as long as 6 months. This has in turn caused prices to rise as distributors get there new stock. We can at the moment still get 7th and 8th gen cpu’s if you want a system build so don’t worry about that.
As for the release of the 9th gen cpu,s they are meant to be released Mid October 2018. These new cpu’s will need mainboards with the Z390 Intel Chipset that will support 8th and 9th gen chips.