@deggie -- I can't say I find your posts particularly helpful in determining whether there is a way to use Lightning headphones on anything but the iPhone 7 and select iOS devices, which is the original topic. What I see is a lot of conjecture and speculation about Apple's future plans which is typically frowned on in these forums.
In response to your most recent post, and with all due respect, someone who thinks there is no noticeable difference between Bluetooth and a wired connection should not be giving audio advice. But let's start with the Audeze headphones (I'm not concerned with the JBLs since Apple does not sell those) -- the app allows for customization of EQ settings in the Lightning cable. I wouldn't expect that to work with the 3.5mm jack. The Lightning cable also provides digital controls similar to Apple's Analogue 3.5mm EarPod controls. Again, that is lost by switching to the Audeze 3.5mm analogue cable. So whether the Lightning cable may be used with an optional app is irrelevant -- they can be used without it. Therefore, using them with an adapter would not impair the use of them anymore than using them on a native Lightning port without the app. Whether or not such an adapter is feasible is a different question. If not, it would seem to be a bit short sighted by Apple. However, since there are plenty of Lightning adapters to other digital audio platforms like HDMI, I somehow think this won't be an issue.
As for your unsupported speculation about whether third party headphone makers will license the Lightning connector, well -- baseless speculation says it all I think.
Also, I'm not sure what you think the W1 chip does in the Beats Solo 3. But it doesn't improve the audio quality. The Beats Solo 3 sound just like the Beats Solo 2. I didn't care for those and I yes I've heard the BS3, and I don't care for them either. Sound is a personal thing, and the reason why there are so many brands of headphones to chose from in the first place. And that has nothing to do with poor bluetooth quality -- but thank you for telling me what I will and will not be able to aurally distinguish. The BS3 is still a compressed Bluetooth signal and sounds like it. And I have a pair of BT 4.1 headphones with which to distinguish the difference. But those don't do much for my 24/48 Aiff and wav sound files.
As for Apple's offerings, well no one knows when the AirPods, or the Beats X or PowerBeats 3 are going to be released. So if I want a BT headphone with the W1 chip, I only have one expensive choice. Which means, if someone wants other BT headphones for their new iPhone 7, they will have to settle for a pair without the W1 chip. Where's the logic in that? Or they can use the included Lightning EarPods until the W1 chipped offerings arrive -- unless they want to use them with their Mac. So now, they are back to one option -- use their old headphones with the adapter. Doesn't make a lot of sense does it? Especially when a simple adapter would solve the problem, from which Apple could make a little more money in the process -- not to mention help establish Lightning as a high quality option to Bluetooth.