Looking over at the Dell XPS line for 2018, the 13's are Quad Core and the 15's are Hexa Core. As such it would be reasonable to assume Apple do the same for the Macbook Pro, ready for the launch of the new Mac OS in Early October. New hardware always comes after the back to school promo's, never during the promo.
In parallel to this I think a huge shift is going to take place soon over to ARM - I think they'll run the ARM based Macs alongside the intel ones for a time. Look at the performance of them in the iPad Pro, iPhone X/8/8plus. They have also gone fully with Metal instead of OpenGL and OpenCL. As such I think these spec bumped Intel machines in October will be the last major bump for another 12-18 months and the completely new ARM devices will be introduced next March or WWDC 2019.