Can I embed a slideshow in PDF through InDesign?

Inside InDesign you can create photo galleries using the Object state Panel, or you can create animation to have pictures that appear and disappear on page. Both this ways can be included in .ePub fixed layout format.

InDesign Plug-in as Mag+, Twixl Publisher, Aquafadas and others solution that allow to create App, allow to create slide show inside InDesign using the Object State Palette and adding different transitions between one picture to another to create interactive slideshows.

PDF is common file format developed by Adobe but used by many other software developers. So even if Adobe will add new features to the Adobe Reader/ Adobe Acrobat, there's no guarantee that other PDF reader programs will support this new functionality...

Mag+ plugin exports InDesign layout to its own proprietary file format which probably use html/css/js/xml — no matter what — what Mag+ export is not a PDF document — it is a unique file format that can be opened only with Mag+ reader.

Have a look at .ePub file format, which is also web based (html/css/js/xml) so you might be able to do what you want with this format. How To Create a Slideshow in InDesign CC for your Interactive ePUB - YouTube

You can also create slideshow with swf file format: Create an Interactive Slideshow in InDesign CS5 with Multi-State Objects - YouTube