Maybe it would be a good idea to take step back and chill too: this debate is quickly approaching the edges of nonsense land.
Stop projecting our enthusiast skewed views and our gamer habits in this discussion.
Um what? Look man, AMD has a major problem in the laptop/notebook sector, and that is the perception that they are second-rate in nearly every possible way. All it takes is someone trying to use a cheap laptop to run a game or two when they will notice that the graphics performance is maybe not so great. How much performance will Raven Ridge lose in a single-channel configuration? At the present, I just don't know. But I can tell you that all APUs are bandwidth-starved from the get-go. Well AMD's are anyway. You lose 10-20% performance on someone's PUBG experience (or worse) and it's a "game-changer" for that user.
You don't have to have an "enthusiast perspective" or reside in "nonsense land" to realize that shaving maybe $3 off the total cost of the laptop to deliver a sub-standard experience to the end user is an awful, awful idea for everyone involved. Some idiot beancounters just don't get it.
When they are trying to shave a few dollars off, it matters. A 2 x 4 GB kit is a little more expensive than a 1 x 8GB kit, and, it means that the laptop must have two DIMM slots. Lots of cost savings there.
Actually, I would think that the OEM would just have one board layout for an entire segment of their laptop line. Since they will sell some configurations with 2x8 GB RAM, they will probably recycle the same board and use it in their cheaper products that are only getting 8 GB of RAM. As many others have noted in this thread, past notebooks have generally allowed a RAM upgrade through the addition of a second 8 GB SODIMM. It goes to show that OEMs have recently sold low-end laptops with 2 SODIMM slots. I see no reason why they would stop now.
Also - consumers do not know what single channel vs dual channel is. They know that 8GB is better than 4GB, but not that dual channel is better than single channel.
They understand crap performance when they (or their kid) decide to push the little budget lappie out of its intended workload range by making it play some Steam title. Which is going to happen, often. Dude comes along with his dGPU-equipped laptop (and there are many in the sub-gamer category) and whoops up on the poor little AMD machine. When this happens, it's AMD missing out on the opportunity to really impress someone. If you can take your discount laptop and make it game "okay"-ish then maybe it raises a few eyebrows. If - as expected - it flounders about with poor/unplayable framerates, nobody is impressed.
So, dual channel memory is something you cannot even market to the average consumer and it costs a few dollars. No wonder they cut it back. AMD might not have the force to be able to say that they do not support single channel memory on the higher end Raven Ridge chips, which is what they should do.
The point isn't to market dual-channel memory configurations. The point is to give the end-user the best experience possible within the price range set for the product.
I do wonder if graphics performance doesn't matter a little bit more than it used to - not in terms of games but mobile phones and things have meant that people paying real premium prices kind of expect everything to be premium.
I don't know that it's MORE important, but with people ditching desktops for mobile devices, I do think that it could be more important. As in, there's no way they're going to put down their lappie and say, "Gee, I guess I'd better get on the desktop to play that f2p game I wanted to check out on Steam". They're just gonna fire it up on their laptop/2-in-1 and give it a whirl.