In Chevy lore, SS means a more sporty and powerful version. For example, the Camaro SS has a 455-horsepower V8. There's definitely no SS version of the 2020 Blazer and chances are there may not be one in the foreseeable future.
Let's not think of it as a continuation of previous Blazer models, since only the name and a general SUV-like design are the main things the new model has in common with its predecessors. This generation launched last year.