As we know Olivia Rodrigo released her newest single Driver's license on January 8th, 2021; and it became very popular on Billboard Hot 100 so that it remained 1st on the list for 8 consecutive weeks.
First of all, the Wikipedia page says:
Nominees for Top Hot 100 Artist, Top Latin Male Artist, and Top Rap Female Artist were announced on April 28, 2021. The full list of nominations were presented on April 29, 2021. The Weeknd is the most nominated artist, earning sixteen nominations.
P.S 1: There is a little grammar error in the Wikipedia quoted text.
P.S 2: The announcement of nominations is after the release date of the Driver's license.
There are so many categories in the awards including Top Streaming Song Artist, Top Song Sales Artist, Top Radio Song Artist, and Top Social Artist (fan-voted), which Rodrigo could be in all of them; because being first on the list for eight weeks results in it stream very much, be sold very much, and beloved by fans very much; or even vice-versa. She could also be in Top Hot 100 Artist because it was the Hot 100 list which the song remained at the top of it for eight consecutive weeks.