No it is a double gauss formula and appears to be the same as used in the 1964 Canonet rangefinder camera where the same optical formula appeared as a 45mm f/1.7 lens. The fifth element is aspherical in the new version. (As opposed to the other Fifth Element which was a rather lovely Milla Jovovich.
View attachment 193781
I don't know what reputation this camera had as far as IQ goes, but I do remember that the simple double gauss 5 element 5 groups 40mm f/1.9 in the 1981 Canon Sure Shot AF35ML was very sharp indeed. In fact annoyingly so; it was better than my Nikkor lenses at the time.
Yeah. I'll say it again... this will be a great lens for RF owners to have in their bag, but don't expect any miracles. That extra aspherical element will no doubt increase sharpness at large apertures, but will also not do any favors for smooth bokeh. I predict the old EF STM version will have smoother background blur, but this new version will be sharper. So pick your poison.
Similar for the RF 85 F2 vs the old EF 85. Sharper yet harsher backgrounds.