This page contains information regarding Star Trek: Discovery, and thus may contain spoilers.
On Twitter, Ted Sullivan used the tag #hoverchair in relation to this character.  That term was previously also used in concept art for a wheelless chair for Melora Pazlar. Though the scene seemed to imply that the character was in the chair due to war-related events, "The Loss" seems to suggest that use of a wheelchair does not disqualify one from joining Starfleet.
Hoverchairs were apparently not a universal norm for Starfleet in this era, as during season two, the character used a more traditional wheelchair.
The wheelchair seen in "Melora" was initially to have utilized anti-grav technology. The chair from "Too Short a Season" was to be pulled out of storage and remodeled. However, the chair had originally been designed with the larger set of the USS Enterprise-D in mind and it was quickly realized that it would not be practical in the relatively small Deep Space 9 corridor sets. As a result, a simplified 20th century wheelchair was used instead. (The Making of Star Trek: Deep Space Nine, p. 108)