Although you directed the question in reply to @Dan_Dube, I hope you don’t mind if I also give an answer, from the standpoint of someone who mainly accesses the Forums from the ZC app on a phone.
While the experience isn’t optimal, I still find it more comfortable and convenient than jumping to a separate browser on the same device. When in the ZC app, one can instantaneously jump to the ZC Home page via the permanent menu at the bottom of the screen and throw out some Ride-ons, look back at some Activities, or quickly ‘Find Zwifters’ to see the rider profile of someone who has posted and whose ride history/activity profile is useful for answering them.
True, navigating across subjects can be a little laborious, but one develops the reflexes to speed up the process, and I don’t find it slower than when accessing Zwift Forums in a tab in FireFox on the same device, for example. For me, doing that provides a virtually identical appearance/experience to the Forums in ZC, with no particular advantage, aside from being able to have multiple tabs open simultaneously.
Sure, the Forums are even more comfortable to use in a tablet or laptop browser, but I would visit and interact far less often during the day if I were limited to those options.
So, if I understand your question correctly, I’d go for option 1., i.e. the status quo.
I hope that it won’t be phased out.