I don't see how this was allowed because there is no safe biking alternative to cross N Washington St.
Having been through three sets of design meetings (a BTD Causeway St design, the CHB design, and PWD North Washington Bridge design) I can tell you that vehicle LOS was the driving factor in not bringing bike lanes through Keany Sq.
The BRA, as part of their Crossroads Innitiative, developed a design for Causeway St including the Keany Sq intersection that brought on street painted bike lanes through Keany Sq.
In the BTD redesign of Causeway (maybe 2011, I can't find the drawings), Vehicle LOS was considered too important and the bike lanes just dissapeared in the last block(s) before Keany Sq.
During the CHB process, the official line from the City was that Keany Sq would be redesigned during the North Washington St Bridge project and that the CHB bike path would head down Beverly to the boardwalk and under the bridge. And yes, they crossed their fingers that the redevelopment, or at least the boarwalk, along the water would be done by the time CHB was built.
During the Boston Public Works redesign of the North Washington ST bridge, the line was that Keany Sq was beyond their scope of work.
Just keep on passing the buck City of Boston...