No, it isn't. If Smalltalk were going to be the future of software development, it would have shown some sign of it by now. All the claimed advantages have been there since the 1980, but in nearly 40 years, Smalltalk has yet to be anything more than a niche player.

Maybe the advantages come with some disadvantages, which wildly gushing articles like this ignore?

OK, there's a new Smalltalk on the market. Unless it knows what the previous disadvantages were, and has fixed them to the satisfaction of developers, Smalltalk isn't going anywhere. This article gives no hint that they even recognized that there ever had been disadvantages.