It isn’t. There is very little reason for an Elixir v2.0 with breaking changes. The language was designed to be extensible and if we need to do major changes to the language to improve the language itself, then we failed at the foundation.
Every time we deprecate something in v1.x in favor of something new, it is literally a step towards 2.0. Elixir 2.0 should indeed be mostly removing deprecated features.