For the headcannon thing: Cybertronian adoption.
So this stems from my own headcanon on Cybertronian Birth.
Adoption is definitely a thing. First off, if a bot is forged grown (which means their creators didn't claim them) they're supposed to be chosen by a mentor, who will show them the ropes. A mentor is pretty much an adopted parent.
Outside of that situation, adoption exists but is rare. Due to how messed up Cybertron is with functionism and stuff like that, mentors abusing the bots under their care or creators abusing their offspring has a huge stigma. Not for the abuser, but for the abused. You're lucky to be chosen, so they can pretty much do whatever they want to you.
Orphaned sparklings tend to fall through the cracks, living on the streets instead of risking an abusive mentor. The reason they are orphaned is usually tied up in Functionism anyway; they've already lost their parents to the system, so why would they trust it?
But good bots do exist. I personally headcanon that Knockout's creators gave up their lifesavings so they could adopt Breakdown from his abusive creator. G1 Prowl adopted Bluestreak after he was orphaned, and was a mentor to Skywarp before the War. (More headcanon of course.)
