upgrade to 2700x or wait for gen 3000's?

Keep your cpu and wait till 3000 launches at computex in june. AMD Ceo has said in an interview that 7nm ryzen cpus with more than 8 cores are coming. Although she didnt specify he many cores, early an 12 core cpu 7nm ryzen benchmark has been leaked. By design, in order for there to be a 12 core ryzen cpu ther must be 2 8 core modules on the cpu, meaning a 16 core will come. AMDs 3000 series cpus will work with existing Am4 motherboards. You will likely need a bios update in order for it to function, but it should work well with any ryzen 3000 cpu, including ones with more than 8 cores.
AMD CEO Lisa Sue said in an interview: "So there is some extra room on that package (the package of the 8 core 7nm ryzen cpu demoed at CES 2019). And I think you might expect that we will have more than eight cores. I didn’t say how many more."
I would hold off and wait till June when they are said to be announced. They sound promising. For example, AMD demonstrated an 8 core ryzen 3000 series CPU at CES. The chip was an early sample so performance WILL improve in the release version. Yet still, the 8 core Ryzen 3000 just barely beat the 9900k in cinebench while using 30% less power. If an 8 core ryzen 3000 beat the 9900k while consuming less power, just imagine how the 16 core Ryzen 3000 cpus would perform.