Tricky decision to play those guys. Southern ought to revisit that rule.
Tricky decision by Southern to play them at Sectionals? Why not, if they are eligible, they can help get the remainder of the team to Nationals, even if they can't play there.
On revisiting the rule, I doubt it. The impression I get is that Southern considers winning Southern Sectionals a bigger deal than Nationals and prefers to allow teams to stick together all the way through that event even if it means the "same" team can't advance on to Nationals. The fact that they may send a weaker eligible team to Nationals than they could otherwise isn't a concern to them.
Is this a recent rule change?
Which? Allowing Nationals ineligible players to play through Sectionals?
The change was a few years ago when early start ratings were done away with. When those were still with us, they were used to get players at the "right" level for early start leagues since these leagues started before year-end ratings came out. With them, the rules were that if you were a 3.5 and your early start rating was a 4.0, you would have to play as a 4.0 in the early start league. If your early start rating was a 3.5, you could play as a 3.5 in the ESL and even if you were bumped up to 4.0 at year-end, you could play on that ESL team as a 3.5 through Nationals (unless you reached the clearly above level).
With early start ratings gone, there was no attempt to get players at the "right" level and instead, National put a rule in place that you would play in the ESL at your current (3.5) level, but if you were bumped up to 4.0 at year-end, you would not be eligible to play at Nationals as a 3.5. Sections were given the option of how long to allow the 3.5 to play as a 3.5, and some elect to allow it only through the end of the calendar year or through local playoffs, others (like Southern) allow the 3.5 to play as a 3.5 all the way through Sectionals.
This has led to several situations where ESL teams are at a significant advantage over Spring teams as the ESL team can have (now) above level players on their roster and dominate through Sectionals, but then their roster may be gutted as far as who is eligible to play at Nationals. In a case or two I think, a team that won Sectionals was not able to field a roster for Nationals and had to decline going.
It seems silly to me to allow players to continue playing at their prior/lower level once they are bumped up if they aren't going to be eligible for Nationals, it isn't fair to their competition trying to make it to States or Sectionals or Nationals, but some sections disagree.