That seems like a scandal if they are looking at purchase history then basing repair protocol on that history
Think of it like this:- You have 2 clients you sold widgets too that have come in for repair. Both widgets are beat the hell up like they were using them to hammer in nails and are both clearly out of warranty repairs.
One customer as other than this widget has 0 purchase history with 5 followers on twitter and the other has been buying goods since you were a start up and has a million followers.
Who would you be more inclined to make sure they are happy and who would you say "yeah I'll fix it, but its gonna cost you" to?
(For examples of something like this, see examples of people going virial on social media because something broke / got banned, timed it right, and suddenly it was magically fixed, within 24 hours, but your avg joe is stuck speaking to a chat bot for months on end).
You would have issues if your warranty said "we will cover you for (random thing plucked out of the air) battery replacements for the first 2 years" but would only replace batteries for your whales as you are in breach of contract with your non-whales.
You have to stick to what you agreed to with your customer in your warranty terms, but you are free to go beyond those terms at your own cost as you wish as customers were aware of your terms at time of purchase.