Reuters reports, citing sources familiar with the central bank's thinking

BOJ

The report says that the BOJ is seen revising up its growth projection for fiscal year 2020 to near 1% (currently 0.7% as per October forecast). The bump higher comes as policymakers take into account the boost from the government's $122 billion stimulus package.

I wouldn't say that this is unexpected but it could end up being a forecast that they are forced to revise lower in the coming quarters if global growth fails to pick up. In any case, just be reminded that the BOJ will announce its next policy decision on 21 January.