Question about Xiaomi Pro 2

Yes, no worries. The electrical system is well protected against water ingress. You just have to watch out for the risk of slipping, as with many other vehicles on wet roads.

Light rain is ok, heavy rain is not, water gets in at the switch where you switch it on and makes the scooter inoperable (tried it myself)...
Newer Xiaomi models are better protected, ride more stable and are heavier.