Well we have what appears to be the official decision on the impending L train shut down. According the the NY Times the MTA will go with the plan that shuts down the L train completely for 18 months. From NY Times:
The decision, which officials planned to announce on Monday, has been awaited for months by riders concerned about the tunnel’s fate. Now, they have their answer: The tunnel, which runs under the East River between Manhattan and Brooklyn, will be shut entirely for a year and a half, starting in January 2019, to repair serious damage caused by Hurricane Sandy.
The times also spoke to the president of New York City Transit, Veronique Hakim:
“It really came down to our wanting to pick an option that minimized inconvenience to the customer,” Ms. Hakim said in an interview on Friday at the authority’s headquarters in Lower Manhattan.
She said she planned to discuss the decision at an authority board committee meeting on Monday.
“This is the, ‘Get in, get done, get out,’ option,” she said.