There are several NCAA eligibility rules that are to be considered. One is the 5-year clock. Once enrolled an athlete has 5 years to get in their 4 years of play. So if a "medical redshirt" is taken in year #1, then a regular redshirt is no longer available.
In rare situations a 6th year is applied for and granted. Those are usually only going to be available if a single injury or medical condition causes a player to miss consecutive years. This is a possibility for Kent since he did not play a single minute in 2018-19. A player can not take both a regular RS AND a medical RS. It needs to be a 2-year medical redshirt in order to be granted a 6th year.
A couple of other rules to consider are that IN BASKETBALL a regular redshirt can not be used in a year when the student athlete plays a single minute (exhibition games are excluded... see the DJ Burns situation). In 2018 this rule was changed in football only. Football players can participate in 4 games now and still take a redshirt for that season.
Another important rule under "medical redshirts" are the limits in how many games the player participated in. They can not play in more than 30% of the games and the medical condition must occur in the first 50% of the season. If Fulkerson had played in just one more game in his first year he would not be eligible to have a medical redshirt that year.