It is not clear on which core the successor of Neoverse V3 (the server version of Cortex-X4, which is used in the latest Graviton) will be based.
Arm C1-Ultra is the successor of Cortex-X925. C1-Ultra has great improvements in single-thread performance, but Cortex-X925 had very poor performance per die area, which made it totally unsuitable for server CPUs. Arm has not said anything about the performance per area of C1-Ultra, so I assume that it continues to be poor.
Arm C1-Pro is the successor of Cortex-A725. Arm has made server versions of the Cortex-A7xx, but Amazon did not like them for Gravitons, for being too weak.
Therefore only Arm C1-Premium could have a server derivative that would become the successor of Neoverse V3 for a future Graviton.
For now, the technical manual of C1-Premium is very sparse. Only when the optimization guide for C1-Premium will be published, showing its microarchitecture, we will know whether it is a worthy replacement for Cortex-X4/Neoverse V3, which had the best performance per die area among the previous Arm CPU cores.
Arm C1-Ultra is the successor of Cortex-X925. C1-Ultra has great improvements in single-thread performance, but Cortex-X925 had very poor performance per die area, which made it totally unsuitable for server CPUs. Arm has not said anything about the performance per area of C1-Ultra, so I assume that it continues to be poor.
Arm C1-Pro is the successor of Cortex-A725. Arm has made server versions of the Cortex-A7xx, but Amazon did not like them for Gravitons, for being too weak.
Therefore only Arm C1-Premium could have a server derivative that would become the successor of Neoverse V3 for a future Graviton.
For now, the technical manual of C1-Premium is very sparse. Only when the optimization guide for C1-Premium will be published, showing its microarchitecture, we will know whether it is a worthy replacement for Cortex-X4/Neoverse V3, which had the best performance per die area among the previous Arm CPU cores.