I suspect Tennessee being unranked is an overreaction to the traditional Tennessee bias, which often saw Tennessee "overranked" in the past five to ten years because of its name and legacy. Upon seeing a Tennessee that clearly didn't look ready to roll at the start of the year, voters have really leaned into "this Tennessee team's not that good" and kept running with it even though UT's straightened out a good bit. And they clearly don't think UT will win the UConn or LSU games, as evidenced by everyone keeping them in "receiving votes."
The real questions to me are these - will voters undercount a possible UT win this Thursday, and only begrudgingly nudge Tennessee into the 20-25 range? They'll say "oh UConn didn't have X or Y" and write it off, even in the face of a team that's 17-6 against the toughest schedule in the sport? I'm guessing that's what they'll do. Again - the Tennessee bias in action. Oh and of course leaving UConn in the top 10.
Heaven help them if UT were to pull off two successive upsets. What's the most a team has ever climbed in a week? You'd would have a hard time leaving an 18-6 UT out of the top 10 if they won their next two games. Not saying that's the likely outcome, just thinking about how much they'd have to over-correct their mistake if that were to happen. You'd go from unranked to 18th-20th to top 10 in five days. I'd love to see it, for obvious reasons.