I'm sure a lot of people are going to lean toward a favorite or specifically preferred "timeline" for alts utilizing Chromie time. For me it's Legion. Legion was when I truly became a capital-A Altoholic and the idea of those familiar, well flowing zones being a singular path from 10-50 means that will be where I level any future alts unless I feel a specific conceptual calling for somewhere else.
I also can't escape the feeling that, BFA and its themes not being something I generally enjoy, Legion is the most advanced and developed leveling game we have access to. Whenever I find myself doing current leveling (pre 9.0) I always dread the leap from "cataclysm" time in the base continents to the BC/WOTLK bracket... which really is the WOTLK bracket to me. BC exists only for dungeon queues once Oculus, Halls of Reflection and Trial of the champion appear in the dungeon queues. Basically I "feel the age" of the older content a lot, and so yeah, I'm always going to lean towards fresher expansions in chromie time because I find that WoW's leveling has gotten better at recognizing an appreciation for time efficiency as it gets older.
What about you? Do you like the newer stuff? The nostalgia of the older stuff? A specific favorite expansion?
And yeah I just noticed the typo in eastern kingdoms. Oops.