I didn't say I assume there's blanks to fill in, I make no judgement, seriously.
There's rumours about Arteta supposedly icing multiple players (Saliba, Guendouzi, Pépé, Maitland-Niles and Auba all told) but only one case where it's been this fatal.
And there's rumours about Aubameyang disgracing himself while on tour with Gabon the other week.
You can readily believe that Arteta's a psycho and the reason we've not heard more about this is there is no more, but I also find it plausible some other issue might be in play—as well as the looming problem of Auba's decline. You can make up what you want, it's a Rorschach blot.
The most interesting solid data we have in the past few days is that Arsenal, Aubameyang and Barcelona all worked hard to make this strange deal happen. Arsenal because we knew it was our one best chance to cut our losses on Auba's contract, Aubameyang because he also knew he wouldn't get a favourable move after six months in at least semi-exile, and Barcelona because they're in crisis. As Goon points out it's no bad thing in purely financial terms.