If you have granted a third-party app access to your activity data, they will no longer be able to display it within their surfaces to any user other than yourself.
I guess you might be able to work around that by ingesting the data rather than using their API or just bypassing it (hey, RWGPS, can you integrate tiling please?) but it's a bit of a death knell for tile bagging sites, no?
So Will that kill the Squadrats leaderboards? I've enjoyed breaking into the top, er, ten-thousand. It's also been useful to look at some of Jonathan France's small tiles to see how he attacked tricky squares.
Strava: API Agreement Update & How Data Appears on 3rd Party Apps
https://communityhub.strava.com/developers-api-7/api-agreement-update-how-data-appears-on-3rd-party-apps-7636
So not-Jürgen being able to see https://squadrats.com/activity/6ap8TmxR603DYOw9hAKB is now banned?