With that kind of airflow and consistent temperature I would suspect the failure rates to be incredibly small on those batteries - typically what kills them is extreme temperatures and high C charge/discharge at high temperature deltas (as measured from 25'C) which is where the cells have lowest degredation, which they should see very little of in this environment.

What would be more pertinent is changing the charging logic so the packs are held at 50% state of charge vs being always charged up to 100%, that will significantly decrease the chance of pack issues while greatly increasing the longevity of the battery itself. If you hold a lithium ion cell at 50% SOC for years without varying it and keep the temperatures flat, it can last for a very long time without capacity degredation. If you leave it at 100% it will be degrade in a few short years and can swell, at which point it has twice the chemical potential to flame out. Also if it's charged to 100% when the datacenter is at 20'C ambient and datacenter cooling fails and temps go up, having the pack warm up to 40'C can overvolt it and that is usually where they swell/fail.

Also fair to note here that Apple is probably at the frontier in terms of using the highest safety cells and battery management logic so I'd feel better about this than I would putting a lesser brand's lipo pouches in datacenter environment.