2021 Elements Organizer and pdf documents?

No change, the recent versions of the organizer don't support the 'normal' pdf format, only the "Photoshop pdf" format which is a bundle of the pdf and the psd formats (the one used when you save in pdf in PSE). There has been no change for the editor, which still works as before, converting the pdf printing format into bitmap.

Why would Adobe ever remove that capability?

Don't ask me why... There is no technical reason from the editor, since you can output normal pdf formats as an option in the share by email feature.

On the other hand, from the editor, if you want to save in the normal pdf format, you only use the option to print to a 'virtual pdf printer' like the 'Print to pdf' function included in Windows 10 or many external add-ons.

The 'Photoshop pdf' format is natively and directly opened from softwares like Photoshop or InDesign, Acrobat, Illustrator. It saves all layers including vector ones. It has always been recognized from the organizer. The drawback is the size of files in that format.

So, you can open any pdf in the editor and save it as "Photoshop pdf" to your catalog in the organizer. I can't see any way of doing it in batch.

I suggest you post in the feedback forum to complain for the removal of the pdf support in the organizer and its dramatic consequences in your scrapbooking tasks.

https://feedback.photoshop.com/topics/photoshop-elements/5f5f2093785c1f1e6cc40873