Doing a Big Bang Release - or Big Bang Adoption - means putting live a large set of changes at the same time.
It is considered bad practice under Agile methodology, which instead proposes an iterative, small Batch Size, feedback-loop-based approach.
This “release policy” is necessarily used in any long-term planning strategy.
It fosters Technical Debt through often required hasty monkey patches, in order to match unfitting, preordained release dates, that did not (could not) account for changes in knowledge and state during development.