I saw Rocky II before Rocky I, I saw Temple of Doom before Raiders, I saw Jaws 2 before Jaws 1, and I saw Superman II before Superman I, and considered the sequels all better then the originals as a kid, cause I saw them more times on TV. As I got older, I started to smarten up as to what is a great movie, and what is average, and after I got to see them all on VHS, I realized the originals of all those movies series are classics.
Kids are going to see the PT, just like they are going to see Batman & Robin(1997) sometime on TV, you just have to let them enjoy what they want, and trust me, in the end quality will ALWAYS win over.
Although I do agree if you can show your kids the OOT first, that is fair because they did come out first.