Yes, but you can use a workaround.
Using the normal way documented by Samsung, you will probably get an error message that the watch is not supported.
However, you should be able to connect the watch via the Samsung Health app (you will also need the Galaxy Wearable / Galaxy Watch Manager app).

This is how the whole thing worked for me on the Huawei P20 Pro, I assume that it should work similarly on the P30.
I can't say whether any functions are restricted, but notifications, fitness tracking, Spotify, Google Pay etc. work for me anyway.