You have to fill out a load chart to fly a plane, they should have to fill out something like a storage chart to get a production allocation. What size are your objects? How many per unit of time and served entity? What is the lifetime of those objects? How is that lifetime managed?
If you agree to add a few months of development time and reduce future velocity to make sure these limits are enforced, sure. Usually adding storage costs about as much as 1 developer’s salary cost for what, an hour? A day?
You missed the part where I said they are "notoriously bad at estimating". We really do suck at estimating everything... storage, work estimates, etc. Why can't we just say "it'll be done when it's done and I'll use ALL the storage until I'm done"?
I mean in my case it was literally a database file filled with the number of (dummy) people who are currently in our org. So that database size was the size of the project. He just didn't plan for the size of backups (backups were his job, not ours).