What if people want AES-GCM on hardware with AESNI and CHACHA20-POLY1305 on all other hardware? Should those be two protocol versions that are both accepted by

What if people want AES-GCM on hardware with AESNI and CHACHA20-POLY1305 on all other hardware? Should those be two protocol versions that are both accepted by everyone and neither is planned to be deprecated? What about Ed25519 vs. Ed448? What if something was deployed with (SHA256 P-256 ECDHE-ECDSA-AES128-GCM), which Google promised to support for a long time, and now people want to switch to djb-blessed X25519-Ed25519-AES256-GCM, will the older ciphersuite be an old protocol version that everyone keeps supporting for >10 years?