PS5's DualSense will be usable on PS3, but not PS4. Sony oversight within days of launch?

Already on sale in some countries of the world, the Dualense PS5 was promptly tested by several specialized and non-specialized users. From the first tests it seems that the controller is compatible with PS3, but not with PS4. This is because PS3 supports any generic bluetooth controller, while PS4 does not allow the new controller to connect. You can see the experiment conducted by the YouTuber MidnightMan below:

Is this a biased Sony oversight, or was backward compatibility with such an older console not considered a problem? We just have to wait for a possible official statement to find out.