Falling behind in software updates is like taking out a payday loan at high interest. For two reasons. One, when you pay it, you owe a LOT more than what you "borrowed" (didn't spend to keep up). And Two, given typical IT staff turnover, the person who did it the last time is gone and the whole idea of catching up is SCARY!
Most of our consulting work to get old, end-of-life directories onto OpenLDAP are MUCH more expensive because they involve upgrades of the OS, the hardware or virtualization technology, and the network. And outsiders have to be called in to pull together the organizational knowledge that was lost to "The Vigorish" of time.
Short answer is:
We've had at least two situations where a user wants to upgrade from OpenLDAP 2.4.40-x to 2.5 (LTS) but we don't package for the old versions of RHEL so we can't get them upgrades on the old OS. But they are having problems (replication mostly) that require they get off ASAP. And the conundrum stares them and us in the face. Now it's expensive and complicated.
Two or three interim updates and this would all have been trivial. Something we do all the time.