I’m not a CPA, but I don’t think you can write off something that already made a profit. How would that even work, if companies were able to write off predicted ad revenue? They could make up any value and never have to pay any taxes at all.
I don’t think write-offs have anything to do with them removing these episodes.
What’s the point of replacing them? The warranty doesn’t keep them from dying, it just means you get a free replacement. The amount of life left on the drives after the warranty expires depends heavily on how they’re used, and most self hosters are pretty gentle on their drives. I could see replacing the drives that are heavily used, but replacing all drives just because their warranty expired seems like a waste of money and effort.