As of version 13.0, AbsoluteOptions is finally updated, and the mentioned issue no longer exists nowadays:

gr = Plot3D[Sin[x + y^2], {x, -3, 3}, {y, -2, 2}];
AbsoluteOptions[gr, ViewMatrix]
(* {ViewMatrix -> {{{0.140687, 0.114308, 0., 0.}, 
                    {-0.0450415, 0.12473, 0.154878, 4.53058*10^-6}, 
                    {-0.0614696, 0.170224, -0.113486, 3.38378}, 
                    {0., 0., 0., 1.}}, 
                   {{2.96386, 0., 0.5, 0.}, 
                    {0., 2.96386, 0.5, 0.}, 
                    {0., 0., 3.04444, -8.27738}, 
                    {0., 0., 1., 0.}}}} *)