You can with a BIOS update, but I wouldn't, as the performance isn't that different from first generation Ryzen, not enough to justify $250+. Hold off for Zen 2 either late this year or early next year.
Yes, Ryzen 7 2700X is compatible with the Asus X370-Pro board, but it is mandatory to update Bios from 0504 to the latest one published on the official website of this product:
I do not recommend the BIOS 3203 unless you install the APU's Ryzen 5 2400G & Ryzen 3 2200G.
According to the latest benchmarks you could increase the performance of your system by ≥ 20% .... but perhaps you should keep in mind:
AMD has confirmed that it will not offer free of Spectre v1 & v2 exploits CPUs until 2019, we are still waiting for microcode updates for the current CPUs that may cause an impact on the performance of the systems as benchmarks have already shown to the systems with software mitigations applied....