Does anyone think it's worth putting some collective effort into agreeing on a list of reprints that are in line with the spirit of FFG's tournament rules and that TO's can use at events and players can reference before hand when building their decks? There's the list that I created by aggregating the efforts of others who prepared reprint lists for the different expansions that is currently posted on www.AGoTNY.net . I think if you remove some cards that are flagged as not proper reprints that it only has cards that are identical or virtually identical to their respective LCG reprints (ignoring art and flavor text differences), but I don't know and haven't done my own vetting to confirm (having not played as long as others, some cards I don't even own to check against). If others can take chunks of the list and do a side-by-side comparison of the two cards to confirm and then inform me, I can update the list.
Of course, to do this, we have to agree on what is and is not a valid reprint. By using "virtually" above, I mean --and vote in favor of including-- cards that have merely typographical style (e.g., using a capital letter instead of a lower case one) or typographical corrections (such as "a" replacing "an" or fixing a misspelling) where there is absolutely no doubt that the reprinted card means and plays exactly the same as its prior version in all game aspects are valid reprints. I think that treating those as valid reprints can be reconcilled with what FFG states re reprints in the tourny rules. However, I would vote that other changes to gameplay relevant aspects of the card including changes that arguably are only for readability or consistent templating (e.g., "lower" to "reduce" and "a" to "one") should be treated as not valid reprints (otherwise you start down a slippery slope).
And I agree that for an LCG heavy meta, it's of diminished value. I'm roughly guess-timating that turnout for Kingsmoot will be 50/50 pre- vs. post-LCG transition players, so sounds higher than what you are expecting. That said, I think the "old" players have pretty much figured out which CCG era versions are "true" reprints and haven't been using any that are not, so hopefully it will be a complete non-issue going forward and at the tournament.
(My exposure only goes back to ITE, so I can spot some of the reprints, but not older stuff and I don't trust myself completely on the ITE and after stuff.)