Usually, yes. But in this case the issue is more complicated. A lot of background can be found in this post: Coroutines and deadlocks - #17 by fvasco
A very short summary is that the project is a programming language interpreter where most values are lazily evaluated. Resolving the actual content of a value can be done in parallel (which is why everything is suspending). These values can be used as keys in a HashMap.
The use case for the sorting is similar. The language provides a function to sort elements, but since the elements are lazily evaluated, they need to call into the underlying evaluation function which is suspending.