I use this new feature in my work to transform a smart object. I wonder if people with old PS version will be able to use this file and edit content of that smart object?
No. It doesn't really work in older versions.
When you use Perspective Warp on a Smart object, it's applied as a Smart filter.
You can open up the file in an older version and see the image with the applied Perspective warp, but you can't edit the Smart filter or the contents of the smart object. It's pretty much equal to a rasterized layer.
Older versions have no idea how to produce that effect, so editing the Smart object contents will essentially disable the Perspective warp.
However, if you save the edited file in that older PS version and open it up in a newer version which supports that Smart filter, you can re-enable it by clicking the eye icon a couple times.