While very customer friendly, this seems to be a rash decision without thinking everything thru. "No" expiration /at all/ means that in 20, 30 or 40 years time, the balance sheet will contain an evergrowing amount of outstanding credit risk. and the database of open tickets will steadily grow with it. At some point in time their accountants will push them to do something about this growing problem. Which will probably result in them limiting the validity to a fixed period again. And taking something away from your customers is never a good idea.

It would have been much smarter to put in an arbitrary limit from the start, say 25 years of validity. That would have sent out exactly the same signal to their customers, with everyone happy. But it would not have put an upper limit to both the credit risk and open ticket database size, which makes it by definition a manageable policy.