It doesn't seem clear that it's not true. We won't know because it most likely won't see the light of day anytime soon. If they had implemented a time limit, it won't be there in the future.
None of the official posting or wording about sharing said anything or hinted at any type of time limit. The limits where probably in other forms, like 10 members max and you probably couldn't change that list often, maybe you had to wait 30 days or something to remove and add someone new for all we know.
The other limit was probably in the form of how many could actually play at the same time. The majority expected it to be you and one of the 10 people which meant the other 9 had to wait their turn and so on. If so then you don't need a time limit at all, why would you? At that point if it's limited to 1 friend at a time it'd be no different than actually lending them your disc like today.
I'm hoping the 'opt-in' feature will be coming myself. Family sharing would be a great feature.
I think the best way to do it, and maybe how they will, is that gold members get it only and that it's only for games you get to digitally which will leave out your disc copies. After that they could have a opt-in that will then let you turn those disc copies into digital and make it how it was going to be originally. I don't think they're going to take very long in bringing back these features they took out, it's not in their long term plan to do so. I think that within 2-4 years we'll be able to select our Xbox One work as originally intended and get all the sharing benefits that come with it.