oldengmkr, that report is rather interesting to this non-pilot for a couple reasons.
I had something modest to do with developing GPS. So I am well aware of the likelihood that planes will end up perfectly aligned vertically if they are on the same track. This raises an interesting question for such cases. Should there be a generic track offset of maybe 400 meters per thousand feet with some mean flight level being on the nominal track so those above deviate port and those below starboard? It should be possible to maintain that separation very closely.
And I also received with interest your primary reason for posting this. I believe some remarks have opined something of this sort is likely to be what happened to AF447. Take the 340s upset and add to it loss of airspeed indication; and, I (still) consider it very unkind for the AP to metaphorically speaking throw up its hands and say, "Pilot has control." That's an inaccurate and impolite way to phrase it; but, it surely gets attention around here when I phrase it that way.