Hi,

While there is no automated way to achieve this you could create a presentation with just the one slide (the one you will be changing) and then in the presentations where you want this one slide to be featured, use the Insert > Object > From File option and ensure you tick the "Link" box. This will link to the original presentation containing the one slide. The slide will be inserted as an image which you can resize to fit the entire slide area.
If you update and save the one slide presentation file, the changes will then filter through to any presentation files you've linked it to. When you open the presentations it will prompt you to Update Links.

Hope this helps.