Strava subscription whebhook on deauthorize

Hello,
I use a subscription to webhook on my webapp and it works very fine, but i have a question about this use case:
- a user in my app decides to deauthorize Strava.
- i do some stuff on its account (unset stored data for this user like athlete id, token, refresh token, expiration timestamp...)
- in the same time i post to Strava API POST https://www.strava.com/oauth/deauthorizewith required data for this user.
At this step all is working fine. The deauthorization for this user is done.
But, few seconds later i also receive strava webhook event on my callback subscription url to inform me about the deautorization!
My understanding of webhook is Strava is posting events to my app when an event for an account registered to my app is happening not in my app but in Strava.
So my question is why Strava triggers this event when the deauthorization is starting from my app.
Thanks a lot for your reply.
Joel (from France ;))