At this point, Bulgaria would check off a lot more boxes than Byzantium would. It has more interesting potential for mechanics and unique infrastructure and units, in my mind, which we know that the devs look for
Bulgaria would also be a new civ, which would be in line with Civ 6’s message, which prefers lesser known kingdoms and empires which were nonetheless extremely powerful and extremely interesting
It also appears in the same region of the world, and despite being undoubtedly less influential, would fit the same victory and specialities (culture, science, faith, production). It would be in the line of selecting Hungary over Austria, for example.
And given the general wealth of hellenic leaders and civs and hellenic-influenced leaders and civs that we already have, I don’t know that from an aesthetic perspective (voice acting, character and building design) there’s as much unique space to explore for Byzantium.
I’m not the most well versed in Eastern European history, but I could imagine that the Kievan Rus could also fit a Byzantium-replacement Role fairly well.
I really don’t want New Frontier to become a pack that gives us Gran Colombia and then brings back returning civs that have cult followings like Byzantium.
I’d much rather see new and unique civs in regions of the world which are underrepresented, with new abilities, units and buildings that we haven’t seen, and leaders that are underappreciated.
Like the Tonga Empire, or Tlingit, or the Chola, or Oman
also, speaking of things that need to be added in new frontier, can the devs please add ways to combat religious victories if you yourself have been converted or if you don’t have a religion? It’s the only victory type that is impossible to prevent in some capacity for some players.