It appears that Smalltalk is still alive and well in a dialect of Smalltalk (ST) called Pharo. The Pharo community is trying to push ST forward with features such as traits, stateful traits specifically. It was discussed previously on these forums that the SK team might implement a form/version of traits in order to promote polymorphic shared behaviors and code reuse. I propose that Pharo be used as an example if ST is a driving influence behind IL. I do not know how much influence ST will have in the new IL, hopefully, quite a bit. The old/new ideas that are coming from the descendants of ST are still/currently really good.
Slides talking about stateful traits: https://www.slideshare.net/esug/stateful-traits-in-pharo