Translation:That would still be valid today.
They are tough, I know. You can hardly translate them, they depend on emphasise, tone and situation. Keep your eyes open for them and don't hesitate to ask what they mean.
I think the problem is that you start to doubt that "auch" even has a place in the translated sentence. I am not sure any more when to leave it in, or forget about it.
In this context, it could either just mean "also”, as in “That would still be valid today, too.”, or it could emphasize the word ‘heute’ and be translated as “even”, as in “Even today, that would still be valid.”