It is possible to use the management API in hooks. That post is just saying that the same tools aren’t available to set up the call to the management API (it just takes a bit more code to get the access token).
With that said, you should avoid making a call to update a user (or send a ticket in this case) because a user may not exist when a post registration hook/action is executed.
Thanks @dan.woda . According to the documentation this hook is triggered after the user is added to the database. I understand that the hook will run async to the transaction so an update is not recommended. But creating a password change ticket shouldn’t affect the user right? It’s only creating a link?