The main innovations in the new, low-latency, DVB DASH seem to be :
1. Evaluating the quality of the path between the CDN and the viewer, and only buffering multiple chunks if the path is an issue. With more and more people running with 50Mbs+ broadband connection with good connectivity not everyone needs to buffer the same amount of data.
2. Using MPEG CMAF for segment distribution, so each part of the distribution chain (encoder, CDN etc.) doesn't have to wait for a complete segment to arrive before forwarding it to the next point in the chain. The segments themselves can be broken down into smaller chunks.
3. Using chunked delivery for the final http segment delivery leg too - again removing the need to wait for a full segment to arrive.
You don't want to reduce the sizes of segments (these are the boundaries that allow you to change bitrate / resolution stream) as the shorter the segment the shorter the GOP length and also the less scope the encoder has to deliver higher quality pictures.
AIUI the demo at IBC is showing DVB-DASH low latency stuff arriving before DVB-S2, whereas previously it could be 30" or more later.