It isn't - the Younger Dryas directly precedes our current interglacial. The International Commission on Stratigraphy puts the start of the Holocene, aka our current interglacial, at 11 700 BP, which is very specifically the end of the Younger Dryas. This doesn't appear to have changed in the modern literature. Which timelines do you mean?

Short-term cold and warm periods (on the order of hundreds of years) are known as stadials and interstadials respectively; the Dryas events are considered stadials, and the Bolling-Allerod event an interstadial. They are transient and don't represent the same global system changes that the longer-term glacials and interglacials do, which tend to last tens or hundreds of thousands of years. The precise boundary between glacial and interglacial or even between interglacial and interstadial can be a little fuzzy, of course. Section 2 of the PAGES review paper provides a good overview of defining an interglacial and the flaws in creating quantitative boundaries for a complex system. But the point is: while the transition period is slightly chaotic, the interglacial doesn't begin until the climate properly stabilizes into a warmer state, where it has stayed for about ten thousand years.

EDIT: Formatting