A long awaited feature is now available in adobe illustrator cc 2018.
In March 2018 Adobe added a new cool feature to Adobe Illustrator CC 2018, With this feature, you can import multiple page PDFs without the need of any plugin or script.
Just go to File Menu – Open the file and follow the instructions
Save time when you import all the pages of a PDF all at once. You can also choose a page range or select individual pages.