Not exactly. Vertical refresh rates are very often 50 or 60 Hz (except for arcade games which are typically weird values). VRR on flat panels will help support that part of video timing. Where things get difficult to properly track is what happens with horizontal scanning. Most game consoles before 2000 displayed 240p60 to displays expecting 480i30. This is where the scanline effect comes from. Also, the pixels were often not square. The display was expected to be stretched to 4:3 but the rendered pixel counts might be something other 4:3 (5:4 in the case of the SNES). By playing on a 4:3 CRT with the console's original video timing you can be relatively confident the pixel aspect ratio is as the artist intended.

Granted the last time I looked at retroarch there were options to handle this and the CRT simulation shaders are in a great state.

At the end of the day the pixel aspect ratio will not affect the gameplay. Hell, there are counter strike players today that still play with incorrect aspect ratio pixels (4:3 render resolution stretched onto a 16:9 display) for no reason other than "some players did it at tournaments ten years ago".