I don't see how a matchup between LSU and Alabama represents a national title when there are at least 3 other worthwhile conferences that don't have a legitimate shot at saying who is the 'best in the nation'. The SEC is not a deep conference and consists of total bottomfeeders after the top 5. Most of their top 5 do not play each other - the two top SEC east teams have a combined 1 game against an SEC west contender (Arkansas). LSU and Alabama each do have one out of conference win with mention.
But let's be honest - you don't deserve a rematch to decide the entire nation when your game /at home/ was a loss.
If the SEC is so good, let them prove it by playing other conferences. Matchups I'd rather see for the national title game more than LSU-Alabama:
1. LSU vs 1-loss Stanford. Yes, Stanford will not play in its title game. However, you have a three-way dynamic between them, Oregon, and USC where they all beat each other. One loss in Autzen (any loss in Autzen looks ugly) is a lot more understandable than a home loss, even in overtime. They also haven't played LSU yet, and Alabama won't play in its title game either.
2. LSU vs 1-loss Oklahoma State. 1-loss AQ conference victor should always have a more legit shot than a team not playing for a conference title with 1 loss already at home seeking a rematch. Big 12 has more parity than SEC by far - Iowa State could have a shot at being an 8 win team right now if it had some of the schedules the SEC east teams have.
3. LSU vs 1-loss Va Tech (revenge win over clemson in ACC title game) - 1-loss AQ conference victor should always have a more legit shot than a team not playing for a conference title with 1 loss already at home seeking a rematch.
4. LSU vs Undefeated Houston - would shut everyone up about Non-AQ teams deserving a shot at the NC for the next 10 years, and would give us a crack at playing Nick Saban in the sugar bowl. This is the way for us to get the most challenging matchup possible.
5. LSU vs 1-loss Boise St - - would shut everyone up about Non-AQ teams deserving a shot at the NC for the next 10 years. Or, will make everyone shut up about the SEC being so good. This won't happen, but I'd rather see it than an Alabama rematch.
See: 2006 for reference as to why 1 vs 2 rematch is never a good idea. If you remember, a certain florida team had a garbage loss to an unranked auburn team...
(CFB needs a playoff etc)