I started watching TOS when I was 11. In those early years it was the cool spaceships, costumes, weird aliens and adventure that drew me in, as well as the straightforward delivery. I didn't consciously appreciate the deeper aspects of the show until I started to grow in experience and perspective. Now I appreciate the show in ways I couldn't imagine when I was a kid.
A kid today could be hard pressed to see what was cool in TOS given the slick productions they've likely been exposed to today. You need to be more perseptive to pick up on the other things going on and that comes with some age and experience.
What could happen is what happened to a lot of us over the years. There were other things I thought were cool back in the day, but as I grew older very little besides TOS still managed to interest me. All the other stuff revealed itself to be mostly shallow beyond the cool visual stuff. Today I see lots of stuff that kids can be gaga over now, but I can pretty much guarantee they will see as silly when they get older. It happened to us and it will happen to the kids of today.
They might also come to appreciate things they overlook now. There are a lot of older films I ignored when I was young, but now I can appreciate them. It happens.
The thought, "I was a kid. What the hell did I know?'
is a recurring one across the generations.