Hi Preethi,
In addition to Paul's reply, I'd like to comment that Photoshop is not - as far as I have heard from GUI designers - state of the art when it comes to design GUIs. There are newer tools out there like Adobe XD or Sketch which are more suited to support the workflow of UI/UX design. So from our point of view, it also doesn't make much sense to have this plugin or that plugin available which support different tools form from different vendors. We simply focus on a very common and basic interface which is a pure and simple bitmap resource like a PNG file. That's it - nothing more nothing less and very easy to maintain and manage as anyone can have a look at those bitmaps with their desired workflows.
I hope I could shed some lights on this and give you more background information on this topic.
Best regards,
Manuel