The main argument speaking against tagging it as a light rail is that commonly light rail infrastructure and rolling stock is somewhere between trams and heavy rail which is very visible in all the example images in this article:
https://en.wikipedia.org/wiki/Light_rail
If you look at "Cairo LRT" though you can see that it's heavy rail infrastructure (high top speed curve radii, high speed catenaries, cross free separate right of way) and heavy rail rolling stock (high capacity with 5+ carriages per train set, much higher speed than trams or even Stadtbahns, larger structure gauge as visibile in the inner carriage width)