Do separate accommodations requests need to be submitted for students who will be taking digital AP Exams?

No. Students who have received approval for accommodations from the College Board SSD office don't need to submit any further requests. Their approvals will apply to this year's digital AP Exams. In some cases, there are designated digital alternatives for certain accommodations (e.g., use of a screen reader instead of human reader). 

Students receive specific digital exam formats enabled for their accommodation if they’re approved for extended time, breaks (extra, extended, breaks as needed), or if they’re approved for an accommodation that requires an accessible format of the exam; for instance, students approved for assistive technology, braille, a human reader, or a writer/scribe, will receive an accessible format that will be compatible with assistive technology such as screen reader software, voice recognition software, or refreshable braille displays.