This is going to sound ridiculous and I'm sure there are a bunch of reasons why it couldn't be done ...
How about having the plate / pcb be 'flippable'. It could land in the case the same way - you just flip them over and then the numpad will be on the left.
The 60% section is not symmetrical, that would be the requirement if you wanted it to be flippable. If flipped the backspace would be on the left, then caps lock would be 2.25u, enter, now 1.75u, and so on if you get the picture. Now someone could design symmetric modifiers, but even still, the alphas dont flip either for their staggering. So unfortunately it would not be a simple thing.
The possible proper way to do it would be to have 2 PCBs, or a scored section on the main variant so you could break it into a 60% and a TK. Then you would need headers so you could connect the two back together after repositioning them on opposides of each other. And all the mounting holes would have to be available for both placement options, and you would still need 2 different plates unless you did a 2 part plate too. But the seam on a 2 part plate would be very visible in the blank space between the halves.
So, possible? Yes. Practical, not so much. It all depends on how much work they want to put into making that possible and if it will pay off with a respective increase in orders.