I’d bet a lot of money that you didn’t and you won’t.
That’s the crux for laypeople, I agree.
Thanks for clarifying. And both, according to you, are entirely postdictions, correct?
Why did you switch from papers V and VI to paper IV, then?
Kindly correct the following sentences from V to make your position clear:
“Overall, the observed image is consistent with expectations for the shadow of a spinning Kerr black hole as predicted by general relativity. If the black hole spin and M87’s large scale jet are aligned, then the black hole spin vector is pointed away from Earth."
“Models in our library of non-spinning black holes are inconsistent with the observations as they do not produce sufficiently powerful jets.”
Analysis of existing EHT polarization data and data taken simultaneously at other wavelengths will soon enable new tests of the GRMHD models,”
" The compact source shows a bright ring with a central dark area without significant extended components. This bears a remarkable similarity to the long-predicted structure for optically thin emission from a hot plasma surrounding a black hole (Falcke et al. 2000)."
" Evidently the angular radius of the observed photon ring is approximately 
(Figure 1 and Paper IV), which is close to the prediction of the black hole model given in Equation (1)."
" In the GRMHD models the bulk of the 1.3 mm emission is produced within 
of the black hole, where the models can reach a statistically steady state. It is therefore possible to compute predictive radiative models for this compact component of the source without accurately representing the accretion flow at all radii."
" Our simulations already predict full polarization maps, albeit for our simple eDF model. Comparison of model polarization maps of the source with EHT2017 data are likely to sharply limit the space of allowed models (Mościbrodzka et al. 2017)."
“…their phenomenology, despite being observed on mass scales that differ by eight orders of magnitude, follows very closely the one predicted by general relativity.”
That would explain it to me.
