Per the article:
The news sent shudders through generations of poets, artists, musicians and others, who felt a strong sense of devotion to A Gathering of the Tribes, a gallery and salon in the building, and to [Steve] Cannon. A former humanities professor, who taught for 25 years at city university campuses including Hunter College in Manhattan and Medgar Evers College in Brooklyn, Mr. Cannon decided in 1991 to turn the building, which he had bought for $35,000 in 1970, into a salon and open house where practically everybody was welcome.
Per the listing at Marcus & Millichap:
• Four Free Market Floor-Through Two Bedroom Apartment
• Approximately 3,000 Square Fee
• 22 Feet of Frontage on East 3rd Street Between Avenue C and Avenue
• Possible Conversion into a Single Family Townhouse
• 1,100 Square Foot Garden Located Behind the Building
Cannon sold the three-story federal-style townhouse to its present owner — Lorraine Zhang — in 2004 believing that he would be able to occupy the second floor for at least a decade.
Meanwhile, according to the article:
"Mr. Cannon said he was exploring whether he had any legal recourse to oppose the sale in court. At the same time, he said, he would reach out to friends and arts patrons to see whether any of them might be interested in buying the building and turning it into an artists’ residence and cultural center."