It's still "callback hell" because you're still fundamentally writing code where you invoke an API and pass in a callback to handle the results. The fact that the callback you pass in happens to be a promise that allows you to stage other callbacks and/or promises doesn't really change things enough for the label "callback hell" to be inaccurate in my opinion.
A different programming paradigm, for instance, would be the use of delimited continuations such that the API you invoke suspends the current call stack, executes the I/O operation, then resume the call stack with the result of the I/O operation. Very few languages support that. One reason is that natively supported continuations in the programming language has far reaching consequences in terms of performance.
I'm not an expert on golang, but I believe this is essentially how goroutines are implemented: https://groups.google.com/forum/#!msg/golang-nuts/t3g8NbITYE...
Also keep in mind that I'm not 100% against callback-based programming. I have, for instance, implemented a non-blocking client for a custom TCP-based protocol using Netty. The client performed better than a blocking version that it was meant to replace. I played around with using Promises in conjunction with the library but ended up preferring callbacks to Promises for a number of reasons, some of which are specific to the JVM.