The phrase 'has been forgotten until' is correct and usable in written English.
For example, "The recipe for kokis, a traditional Sri Lankan cookie, has been forgotten until recently."
Hall had been forgotten – until the very different case of Edward Snowden brought the intelligence community back into the headlines.
Saved by a doctor who worked at the hospital in the 1960s, the drawings had been forgotten until the American Folk Art Museum's Ramírez retrospective last year piqued the memory of the doctor's daughter-in-law.
After this period this poetry seems to have been forgotten in Wales for centuries until Evan Evans (Ieuan Fardd) discovered the manuscript in the late 18th century.
Kim Willsher writes: Le Parisien newspaper described the prize as "revenge...for an institution that until now had been forgotten" by the Noble committee.
The year after Confederation, arms were granted by Royal Warrant on 6 May to Ontario, Quebec, Nova Scotia (the fact Nova Scotia had been granted arms had been forgotten, and it took until 1929 for the historic arms granted in the 17th century to be reinstated) and New Brunswick.
All women who populate microhistory "have been forgotten and silent for so long," because until recently history was not about them.
