NFPA 70E Table 130.5 and 130.7 list out what types of Arc Rated PPE are acceptable to use for protection from an arc flash. Long coats are not listed in either of these tables and should not be used due to the limitations of this type of design. To learn more about these limitations please see the white paper Long Coat Protection concerns.
Additionally, CSA Z462-21 also has Arc Flash PPE Selection Tables. Table 3 and 6C do not list long coats as an approved type of Arc Rated PPE.