Agreed. Rust 2019 would seem brand new, shiny, trendy and cool for a whole year 2019. Rust 2018 will be like cars at the american car’s dealership, that sell at the discount because next year is already here. (I bought 2013 model car at the end of 2013 for this reason - trying to thrifty, and it was September, so people consider September a end of the year, and dealerships sell next-year models already)
I know it’s stupid, but that’s how human psychology works. And languages live or die by popularity. Anything that can catch an eye of developer and bring it to try Rust counts, multiplied by millions of potential developers.
With such a schedule, I think it’s still doable, fair and worth it to rename the edition to be 2019, and I think it’s a great idea.