Upon this occasion, the newly instated minister T'Pau began cleaning house, which resulted in many former High Command ships being undercrewed by the time of the Babel Crisis. During that incident, she was only able to dispatch twenty-three starships to add to a combined Andorian-Human-Tellarite intercept fleet. (ENT: "United")
This implies that either the High Command was re-established in some form, or that Lorot was somehow assimilated before 2154, long before official first contact between Starfleet and the Borg. If the former, then Vulcan Space Central and the V'Shar might also operate under the authority of the High Command. It should be noted that Vulcan maintained its own fleet of ships separate from Starfleet as late as 2368, as seen in TNG: "Unification II".
This implies that the High Command was either reinstated after 2233, the point of divergence, or it was reinstated in both universes. As noted above, the latter possibility would facilitate Lorot being assimilated after Starfleet's official first contact with the Borg.