Will this have any bearing on cosmic distance scale measurements? Is it possible previous events that were thought to be supernovae, and included in the data used to determine cosmic distances, were actually accretion events? Is all the data from last century preserved in such a way that it can be revisited and analyzed anew? If not, should those old measurements be discarded?
These events may be rare but, seeing as how recent estimates suggest there are about 2 trillion galaxies in the observable universe, you have to figure something like this is happening at some point in the universe at almost any instant in time. Even if there is, say, a one in 2 trillion chance for a solar mass or bigger accretion event in a galaxy in a given year, it will mean we should be able to observe about one of these per year.
Also, seeing as how quasars were likely megascale accretion events, and AGNs were/are diminished versions of that, and so on, it suggests accretion events were more common in the past (which squares with the notion that spacetime is expanding, and that there was a more even distribution of mass before so much of it was locked up in black holes), so, even if the odds of accretion events are remote now, they’re certainly more common as we look at galaxies a billion or two billion or four billion or more lightyears away.
Given all of that, it seems very likely that old supernova datasets could be corrupted by instances of accretion events. What’s more, if this one was 100 times as bright as a typical supernova, and it was triggered by a one solar mass star, perhaps far more common red dwarf accretion events could end up being closer to the brightness of a typical supernova. There are, after all, far more red dwarfs out there to get consumed by black holes.