Right, because Intel hasn't yet released any mobile chips that support 32GB in 2 DIMMs. Well, other than the i7 in my wife's gaming laptop, which was already an older model when I bought it for her more than a year ago.
Right, it's Intel's fault Apple doesn't sell laptops with the maximum amount of RAM possible. You know, just like the 2011 MacBook Pro I have sitting next to me could only possibly use 8GB of RAM (again, due to Intel's limitations, supposedly) but it's been running just fine with 16GB (and able to use all of it as well) of aftermarket RAM for 6 years.
No QUAD CORE, KABY LAKE's (or later) that supported more than 32 GB, sorry. That's what Apple was counting on.
And the much lower power consumption of the Kaby's was ESSENTIAL to Apple meeting the THERMAL BUDGET for the design.
And THAT was ESSENTIAL for the 2016 MBP's being able, unlike its 2015 predecessor, to run full-tilt, with NO THERMAL THROTTLING of the CPU nor GPU, making the new MBP MUCH faster in SUSTAINED high-demand Applications than its predecessor, EVEN THOUGH THE CPU IS ABOUT 8% SLOWER.
And IIRC, your 2011 MBP only supported 16 GB after APPLE released a FIRMWARE REVISION. So perhaps it just took them a little bit to develop and debug the firmware patch, "Qualify" their memory controller with a good sampling of different memory modules, and get all the sign offs necessary to push out something as potentially catastrophic as a "BIOS" update. Perhaps they didn't feel they could get all that done by the initial engineering cutoff (freeze) date. So they shipped with an 8 GB limit at first.
So, sounds like "Engineering in the Real World" to me.