It looks like a strong chip. They are pretty much jumping one or two x86 generations with every release, sort of like what Apple did for many generations in a row starting with the A6 or whatever.
One difference here is that Amazon isn't actually designing the cores: they are using Arm reference designs: in this case the N1 Neoverse, and building around that.
They may do it at some point, but perhaps the path of least resistance so far is to use the existing core designs, which are not bad at all and getting better and spending their effort on the uncore and offcore components which don't have off-the-shelf designs just sitting there and which are very important for server parts?
