LPDDR4 is supported by some Intel CPU's but overall memory support across intel CPU's is pretty inconsistent for no apparent reason since they are all based on the same core design.
That said you won't see any difference in performance between LPDDR3 @ 2133 mhz and LPDDR4 at 2000-2400mhz.
It's likely not even in full production since the roll out was announced a week ago.
Also no where does it says the speed and bandwidth they'll support, overall there isn't much performance difference between LPDDR3 or 4, or between DDR3 and 4 when the frequencies are off by only a few 100's of mhz.
That said I'm actually disappointed that the memory on the MBP especially the 15" is LPDDR, no reason to degrade memory performance on a machine which already has a pretty big battery, DDR4 is pretty darn power efficient as it is.
This to me looks more like another cost cutting decision set by Apple to simplify board design and the supply chain.
No 7th gen CPU's, low power memory for no reason, dumping of ports, and a pretty steep price hike.
I'm glad I bought my mid 2015 pretty fully upgraded MBP 15 with a dedicated GPU for 1480 GBP on sale last holiday season, this one is not even meh, it's a full on pass, the only feature I like is the touch ID, I still don't understand why Apple doesn't allow you to unlock your Mac with your phone, but now I know why.
Low-power memory is kind of a big deal because unlike the CPU, memory doesn't sleep. Even as it is, I expect big battery life regressions relative to the already inadequate 8-9 hours of the 2015 models. Apple cut the 13" model's battery by 1/3 and the 15" model's by 1/4. No reason losing even more battery life by ditching LPDDR3.
As for the 7th gen CPU--there are no available quad cores. I don't think Apple wanted to release redesigned MBPs with the 15" flagship model having a CPU one-generation behind the 13" model.
While memory doesn't sleep, DDR4 supports Deep Power Down and Low Power Auto Refresh even in the non-LP form factor (this is 50-80% power reduction, there are also variable timing modes which can be used to reduce power consumption during normal machine power states).
I am ok with the LPDDR3 being used for the 13" one, but on the 15" they should've went with DDR4 tbh.
As for the chips yes no quad cores for KB yet, but then again I don't understand why they didn't just staggered the release like usual, MBP13 can come out with Kabby Lake Dual Cores and the 15 can come out later when the QC's are out which is December this year.
