Not disagreeing with the general concept - these IDs leak information - but these are sequential IDs, not auto-incrementing IDs. The leak is the time the ID was generated, not the volume of IDs generated.
That's still a competitive risk -- it does things like reveal if a given list of customers from recent orders/posts are all new customers or long-term customers.
Or from a list of most recently added customers/users, you can figure out the rate of signups.
Revealing timestamps is bad because it can reveal way too much information about the health of your business that you prefer to keep private, if a sequential list of ID's ever gets exposed (which is hard to prevent).
