This answer only deals with the attribution part. This announcement seems to indicate that the latest iteration of the AI assistant now supports attribution. I don't think it does. I think regarding attribution nothing fundamental has changed, just a few rearrangements. That's why I'm confused and not sure what you really mean here with "rebuilt for attribution". I think this is wrong.
The LLM part is the same as before, no attribution at all. It just appears less often. The (more or less or even not) relevant answers part with links to the answers is also the same. It only appearappears earlier and is additionally summarized. The summaries seem to have links back to the answers but these links are already contained in the linked answers. All in all, no additional attribution information is given in this iteration of the assistant compared to the previous version.
Finally we hear a "...LLMs cannot return attribution reliably...", which is a departure from previous statements, but otherwise the only difference is that additionaladditionally quotes from answers are taken and referenced. One could argue that this increases the amount of attribution, but one could also argue that it does nothing to solve the general problem that LLMs cannot return attribution reliably unless for example you would stop using them. Are you willing to do that? I guess not.
And finally: I would not give attribution by making multilinemultiple line spanning texts a link. Rather use quote styling and put source information below. Something like.
This is a relevant quote from somewhere.