Memphis Shelby County Schools have tons of optional schools. Kids can attend any school with an optional program where they are "accepted".
Any student can claim homelessness. Even if they are not homeless. In an urban area, a kid can move schools, use a new address that is a shared residence, grandparents, aunt/uncle, brother/sister, church member, guardian's coworker, etc... no one is going around from the TSSAA checking to see if the kid lives there.
The municipals like Bartlett and Germantown Municipal have open enrollment. So they can get the kids early and not have to worry so much about all of that. The private schools poach kids young too. The public schools will recruit your kid in the handshake line after a game.
I don't know why people complain so much about this. If you don't understand the contrast of rural TN to urban TN then move to the urban area so you can partake in the same shady dealings.