Pursuing gradual typing makes sense when you've got an established dynamic language and want to incorporate typing into it (forget Elixir, let's just look at the massive success of TypeScript). But as OP's recommendation says - "for new languages", gradual typing has lots of costs and fewer benefits.
To put it in other terms: my informal impression is that the dynamic "features" of TypeScript are used grudgingly; the community strongly pushes towards strictness, eliminating anys, preferring well-typed libraries, and so on. There's little appetite to - in a single project, unless absolutely required - mix-and-match dynamism with staticness, which is the thing that gradual typing gets you. Rather, it feels like we're migrating from dynamic to static and gradual typing is just how we're doing the migration. But in the case of a new language, why not just start at the destination?
To put it in other terms: my informal impression is that the dynamic "features" of TypeScript are used grudgingly; the community strongly pushes towards strictness, eliminating anys, preferring well-typed libraries, and so on. There's little appetite to - in a single project, unless absolutely required - mix-and-match dynamism with staticness, which is the thing that gradual typing gets you. Rather, it feels like we're migrating from dynamic to static and gradual typing is just how we're doing the migration. But in the case of a new language, why not just start at the destination?