I noticed the same problem.  With the new Outdoor Rowing activity on the watch collecting the GPS data I expected this to be exported to Strava as with runs / walks / cycles etc.  I don’t know if this is an Apple or Strava issue, ie is Apple sending the map and Strava is not importing it or is Apple not sending it? 

I also do paddle sports and am frustrated with how Strava is importing this type of activity. For me it is is recognised as a generic ‘Activity’ type and no distance, speed or map information is imported. I have gone through all of the steps of turning on and off workout route information etc through Apple Health settings. Reinstalled the app, reconnected health etc etc. Still no joy. Strava recognises all the right data for running. And Apple must be making this data available because I have 2 other apps that correctly import all the data Apple is making available (map, distance, speed etc). And they recognise the activity type as paddle sports. Seems very odd that the biggest app of them all isn’t up to speed with this.