I think so too.
North up is the conventional reference for displaying directions on a map. This is what I asked for and for a while this North up was the default in the browser version.
But when the Route Planner was added to the mobile app, the setting reverted to the Left to Right setting.
I think if you change the default setting now, aviators who use that default setting won't have the wind direction they're used to having. I don’t know how many they are, I just remember one aviator requesting North up as default in the forum. However, this would avoid many posts on the forum by sailors and hikers. And also the misleading to Windy users who are never posting.

For Route planner for boat

And for hike/car

A visual indicator of the direction reference setting would be desirable without having to check that the correct reference is active.
For Left to right default setting it could be …

For North up setting …

For Bottom to top setting …

…. With a short explanation when clicking this red letters area (I can imagine the text).

It would be very useful for new users of the Route planner with boat (90% of posts about this question of direction reference are from sailors). This would avoid the many questions on the forum about the “wrong direction” of the wind and waves in the Route planner but also the many likely drops-out by those who do not post on the forum about this apparent inconsistency.

From time to time, check if the setting is still North up.
Once I noticed that it had come back to the default setting.
As already said in the past it would have been preferable if the default setting was North up. But it would be tricky to make that change now.