Ruger has been saying that since time began . In reality 99.999% of cylinders time just fine . Most timing nowadays is a result of drop in parts and gets no adjusting. The issue is usually the cylinder length which gets adjusted to fit the gun. If you can find one with little to none endplay or too long needing trim it would be a simple thing.
But ,,, Ruger cylinders are around , NAA cylinders pretty much only from the factory unless you have a donor gun.
So it seems their lawyers get to make the call.