Well no sh*t: memory rated to run at 8533Mhz, in a much smaller (and currently niche due to how new it is) footprint, is going to be considerably more expensive than memory rated to run at 5600Mhz in a comparatively massive dual SODIMM configuration.
No mention of the fact that the Intel platform requires much faster memory either; 5600Mhz is basically a non-starter on it, and doing a quick price check shows how much more expensive SODIMMs get at 6400Mhz too (not currently aware of any faster, but I imagine 6600Mhz+ would be even more expensive; wow, imagine that!), thoroughly invalidating any complaints against the much faster LPCAMM2 modules.
Top notch journalism here folks... Water is wet, LPCAMM2 is superior to SODIMM. Hence, it is more expensive!