Traditionally, US lawyers practiced in firms organized as partnerships. The members of the firm were called partners (sometimes senior partner, etc.) and employed lawyers were called associates. The term "of counsel" might be used, with variations, for a lawyer loosely affiliated with the firm in some way but who was neither a partner nor an associate. Such a person, sometimes a former senior partner now in semi-retirement status, might be said to be counsel to the firm, but it wouldn't be correct to say the position is Counsel.
Subsequently, some law firms organized as professional corporations, more recently many are LLCs or LLPs. Many have operations in many cities, even countries, with lawyers who are integrated into the firm in varying degrees. Some associates are now "promoted" into a status lower than that of traditional partners. The old terminology doesn't quite fit, so a wide variety of new titles are now encountered, with wide divergence in meaning. A lawyer might be called an owner, an equity partner, a senior something or other, etc. Some firms might have a specific status they choose to call counsel. Good for them, but the meaning isn't necessarily clear to anyone outside that particular firm; it might be a relatively high or low position (but above associate). Promoted might be the correct verb if a person who held a lower position in the firm now has a higher position (other than partner), but not otherwise.