The report notes that the survey is expected to be used as a basis for discussions when the BOJ is to meet with bond market participants on 9-10 July. The sources add that the survey is asking market players about their expectations on the range and pace of the tapering process.
As they look to take this next step, it's just prudent to get some idea of what the market is expecting. There's nothing peculiar about this and it will just help smoothen the discussions in two weeks' time.