According to June 17 NY Times article:

Why This Overlooked Residential Island in N.Y.C. Wants Tourists

With a tech campus, a chic hotel, ample green space and its famous tram, Roosevelt Island would like more visitors, please….

… Although many locals are thrilled about the attention the island is
getting, the population of around 14,000 is still not enough to keep these new
businesses thriving, said Shelton J. Haynes, the president and chief operating
officer of the Roosevelt Island Operating Corporation, which functions like a
local government.

These small businesses definitely need tourists to come in, he said. Many were hit very hard during the pandemic. Especially now, they need a hybrid of residents as well as tourism to stay alive. The corporation is considering a series of free tours, both on foot and by bus, to bring in more people, Mr. Haynes said.

UPDATE 6/20:

I asked Roosevelt Island Operating Corp (RIOC) Public Information Officer Amy Smith:

Shelton is quoted in June 17 NY Times article about Roosevelt Island wanting more tourists as saying there are around 14 thousand residents living on Roosevelt Island.

Where did he get the 14 thousand population number from?

Is it from the most recent census or a statistic from RIOC?

Ms Smith answered:

You are correct that 12,000 more closely reflects the 2010 census data
and Mr. Haynes was misquoted. Weve reached out for a correction.