From what I understand it's part of an inherent design of the camshaft being so far away from the lifters, unlike a small block Chevy for example. Since the lifters are fed oil by oil splash from the rotating assembly, that they can be starved of oil if you idle too long with lower oil pressures. 1,500 rpms or higher is needed to keep it well oiled.
They introduced higher quality roller pins, a few years ago, but that won't help if they aren't getting enough oil. It's recommend that you occasionally rev up the engine to get the upper part of the valvetrain lubricated well, use a good quality synthetic as well to help with this. Essentially gun it from time to time when you can do so safely is the most common layman advice. Most of us do that anyways, since it's a Hemi and kinda the point right
As 2020Big4x4Horn mentioned, he ran his 03' hard, which is why he probably didn't have a problem. He got it well lubricated, it's running it too gingerly that may cost you.
Of course no one actually knows of the current Hemi engines in the DT gen RAMs have been "upgraded" to fix this issue in some other way. It's one of those wait and see as more and more current gen RAMs rack up the mileage. But I'll be listening for that Hemi tick each time I cold start my truck, just in case.