This is a good point Markus. To be honest, I really don't know until the task is initiated, however I think to answer that question properly we are looking at a case-per-case basis.
The more I think about it the more similarity I think two JIRA issues bare e.g. this one and NUTCH-881 (if we are to seriously consider achieving this). It would be great to have these tasks done before the next release, however NUTCH-881 can be done in incremental stages, unfortunately it may not be the case with NUTCH-865 and a contingency period would need to be allocated to safely guarantee that no patches were effected in the process of resolving this ticket.