Whether R7RS-large will ever be completed is now a big question. Here's my quick and dirty summary of recent events.
Until last fall, the R7RS Working Group 2 was regularly voting on libraries and features to add to the standard. (See this page for the results.) There were complaints about this approach, and, last fall, there was a major shake-up. A new effort was started by Daphne Preston-Kendall and Marc Nieper-Wißkirchen to split R7RS-large into two languages, Foundations and Batteries. Both are supposed to be compatible with R6RS, which was not originally a goal for R7RS-small or -large. The goal, in part, is to "heal the split" between R6RS and R[57]RS in the Scheme community. Marc, Daphne, and others are working hard on these languages, but there's no sign of the split healing. Some implementers remain complete opposed to a Scheme based on R6.
This past week, John Cowan resigned as chair of Working Group 2, saying
I do not think that there is any further hope that I can get sufficient agreement among the different players to have any hope of coming to a conclusion.
At this point, the Scheme Steering Committee, the group that organized the R7RS project, must do something to keep R7RS-large afloat. No-one's heard much from the SC in years, however; according to John, they haven't spoken as a body since 2013. Thus it's currently unclear whether there will be a new chair or any further work on R7RS-large.
Regardless, work on the Foundations and Batteries languages continues. Whether this will lead to an officially-blessed Report is anyone's guess. The old R7RS-large voting schedule has vanished with John's resignation, though, so it's the only game in town for now.
I hope this is some help. Daphne has just written her summary of the situation here.