So, from my understanding, the idea of 'filial piety' is sort of a cultural or religious practice where there is a certain expectation held over the children. Who cares for who depends on who needs the care, and it's assumed that the adult children will reciprocate (balanced!) the care to their parents, as a repayment for when they were younger.

My first question, which I'm hoping will be answered later in this article - are families hiring migrant workers, or are they the only ones willing to take on the care of Shanghai elders because of other reasons? Also, this tells me that the people likely being researched for this article are Chinese elders and migrant caregivers.

I think the author is trying to say here that building a rapport with non-familial relatives can, over time, create a bond just as strong as one between blood relatives.

Deeper (platonic or familial) relationships form due to more intimate nature of providing care to another person, at least when the caregiver has some empathy.

research takes place in Shanghai, China, one of the country's largest & most urbanized cities.

I think what this line is trying to say is that this article will have some first person POV's from the migrant care workers, and how they have formed kinship, or a close relationship, almost familial, with the elders they care for due to how closely they work with them.

This line reminded me of the two years I spent volunteering in a nursing home. Getting to know the elders of my community was an experience I wouldn't trade for anything. They're so full of knowledge and inspiration.