As someone who is more of a free rider to the newsletter (*blushes*), I might not have as much of a say in this, but I agree that a peer review is different than an encyclopedia article. I'd like to think that a peer review or editorial doesn't proceed according to the same kind of more-or-less universal standards and processes that govern encyclopedic work, and thus make it modular enough to support a collective author function.
And there are many spaces in Wikipedia (and thanks for the cite, Taha :P) where individual editors write statements themselves, where it is incredibly useful to represent the opinion of a single individual. The Signpost [0] has bylines. Beyond that, Articles for Creation reviews [1] and Third Opinion [2] are probably the best analogies to research newsletter reviews, but this also takes place in X for deletion nominations, Arbitration Committee statements, and more.
I think in the grand scheme of things, it is actually productive to have somebody be able to say something a bit more opinionated like "it is disappointing that the main purpose appears to be completing a thesis, with little thought to actually improving Wikipedia", because as we see here, that leads to fruitful conversations. But I do think that they should be attributed to the opinion of an individual, who can then further discuss this opinion publicly.
There is certainly room for collaboration in reviews, and there can be co-authored reviews. However, if someone is listed as an author, then maybe they then have a kind of responsibility for the content. If they just edited it for grammar, etc., then perhaps they can be listed as an editor. Just some thoughts.
Also, I totally agree with the research awards, perhaps more thoughts on those later.
Best,