As far as the OP is concerned, I think these are really just called "bluetooth speakers" nowadays.
In practical terms, I agree in a large sense, but Bluetooth is an input, not a cabinet design or driver layout. I was genuinely curious whether this physical configuration had any particular name, since it of course in principle can be constructed without any Bluetooth receiver.
By the way, a web search with key words "bluetooth speakers" mostly produces products in two categories, one being a genuine stereo speaker pair with a Bluetooth input, the other being a small battery-powered device, very much as a modern-day boom box, of very low cost and basic construction, suitable for outdoor recreation, and the like. Neither of these two broad categories quite encompass the description I gave. Hence, I think, a new name is badly needed.
Of course many, especially in this community, would have limited interest in such a configuration, but in my view it may not be as frivolous as some might assume. Once getting passed the idea that not every room in the world is as meticulously arranged as an audiophile’s living room (I know, it’s hard), and thinking about spaces like kitchens, hallways, and bedrooms, where a transistor radio would have been common in yesteryear, I think that some would start to see the usefulness. I think many are still unaware that an appliance as small as 50 centimeters long, smaller than a mobile phone, in fact essentially a phone with no screen or battery, can easily provide the audio source, connecting to a local media server or internet radio channel. Functionally, the effect is the look of a mid-century radio box combined with the ability to play an uncounted variety of of live or recorded sources.