This has been true for some time. Very low interest rates mean that the price difference between leasing an old vs new aircraft isn't as big as it used to be. So once an aircraft is past its first lease, the bean counters at the leasing firm will do the sums to see if better to lease again, or break for spares. Some of the big boys own their own parts/ breaking firms.
Legacy airlines are more likely to own their own aircraft, so the maths for them is a bit different. So you see FSC airlines keeping aircraft longer than LCC. (plus they have their own in house maitenance arms to be kept busy)
Plus spare parts price >> parts sold as original equipment
There was a case where (I think )P&W didn't have a tight contract with a Japanese airline on reselling. The airline purchased extra engines as part of the deal, then as soon as they were delivered nroke them down, sold as spare parts, and made a nice little profit...