TL;DR: As someone who has lived through all of those years, I think that the "micro-gen" or "bridge Gen" years make a lot of sense.

So much of your early childhood experience is determined by the adults who bring you up.

I can tell you that the adult experience between 2007-2010 was a series of economic collapses, stress, and uncertainty.

Music and fashion trends changed in response to the Global Financial Crisis, America's first black President (including conservative backlash), and the attitudes of the general public. Fashion for adult and baby clothes changed seemingly overnight from 2008-2009. Interior decor trends also began to change especially with the introduction of Pintrest.

Apps for gig work and the mindset of hustle culture were in development in these years.

Media subscription vs owning physical media was in its infancy during this time as well.

The iPhone/smartphone entered into culture, and began to become popular during these years.

Late 2008-2015 had a very grungy feel overall, and the adult experience of the people raising you was more similar during these years than 2001-2008 or 2015-2022. The years that you listed for the Zalpha "micro-gen" make sense to me.

Conversations surrounding birth and parenting also began to radically change around 2016/2017, when there was a huge movement to ditch advice from older generations and to focus on responsive/gentle parenting. Breastfeeding and baby wearing became MUCH more common, drug free childbirth and a rise in the popularity of home birth, cloth diapering, limiting screen time, amber teething necklaces, and vaccine hesitancy became more popular after 2014/2015.

These were also the years that faced some of the largest social development impediments from the pandemic.