As far as I see it the re-introduction of an “old” feature needs to be done somewhere and since they were working on the to-be-released-soon device they started there. Seems logical to me.
Additionally: With the OB2 development still ongoing the OSes of the older devices are still a moving target. Introducing new features while still working on another large (feature like Overbridge mode) is much more error-prone, so it make sense to do it not in parallel, but one after the other. Since the new device doesn’t support Overbridge mode it make sense to re-introduce it there. Again: seems logical to me (as I’m a software developer myself).
When looking around almost no company provides useful updates to their devices. Most companies don’t even provide bugfixes, but want you to buy their next model to get stuff fixed.
That’s the sad reality we live in. Am I happy with this? No, but I vote with my wallet.
It doesn’t matter how long a feature already got requested for a device. When it’s not there in the beginning (and wasn’t promised like OB2), then that’s what you have bought. There is no type of entitlement for anything. You can ask for it and it may be given to you, but all of this takes time and then it’s still a freebie of the company doing so.