I'd say the faster the better. Ryzen CPUs seem to be quite RAM speed hungry with noticeable differences at faster speeds.
If you motherboard can already support 3200 (or more), great. If it can't, it might with a future BIOS update. Even if it doesn't, the RAM will still work, just clocked at the fastest speed the motherboard will support. It's a better option imo than buying slower RAM, receiving a BIOS update that supports the faster RAM speeds, then having to replace the RAM if you want the performance boost.