Another potential reference to the PT, in the same breath Luke says that Obi-wan was responsible for the training and “creation” of Darth Vader. I feel like that word specifically (creation) implies the events of ROTS.

Personally, I like the PT references. Quality or not, they’re part of the franchise and part of the lore. I always thought that the fallibility of the Jedi was one of the most interesting aspects of the PT (yet of course not really explored there). One of my biggest hopes for the ST before I knew anything about TFA was that Luke would in some way address the failures of the Jedi of the past in training the new generation of Jedi. So this satisfies me quite a bit.

They also explain “balance” here better than in all the PT movies combined (though it’s still, of course, vague).