This question was asked in the 'How to optimize a system with the latest ARM DynamIQ processors' webinar. You can view all other related questions in this blog post.
This is true, most recent premium mobile products advertised in the press with LPDDR4 technology do state LPDDR4 with 2-channel at 32-bit data width. ARM system guidance states LPDDR4 with 4-channels at 16-bit data width for premium mobile. But these two definitions are aligned, as although LPDDR4 devices may appear as 32-bit data width, they are actually two independent data channels at 16-bit. So ARM system guidance is fully aligned with the market in LPDDR technology choice and configuration.