The harsh, deliberate (don’t know if those are the proper descriptors) style of the dance sequences added a great deal to the atmosphere of the 2018 version of Suspiria for me. I assume it's some type of ballet, but was it just random ballet dancing or a specific style of dancing?
Basically, it's contemporary with references to expressionism and hints of Indonesian.
From the choreography Wikipedia page for Suspiria (2018):
Guadagnino's Suspiria utilizes dance as a key plot device. Congruous to the period in which it is set, contemporary dance was a central influence on the dance style depicted in the film. Kajganich commented that German expressionist dancers Mary Wigman and Pina Bausch were specific influences on his conceptualization of the dance routines. While writing the screenplay, Kajganich shadowed choreographer and dancer Sasha Waltz to gain further insight into the technicalities of the profession. The work of Isadora Duncan was also an influence
For the last sabbath scene, Jalet said :"We wanted to go from something pretty technical, mathematical, with a certain sense of elegance to something where the body becomes wilder and more and more distorted,” Jalet commented. "The scene described something very chaotic, but I felt we needed to create something still very ritualized." Indonesian dance also served as a reference point for the sequence, which features movements that are "staccato, with harsh stops and starts, and an arm styling that is both intimate—in moments when the dancers hold on to each other—and harshly linear."