"Fix" and "consult" are two VERY different things. Lucas wasn't "brought in" to "fix" a mess. Abrams and Terrio are telling the final installment in a story Lucas began, so they simply asked Lucas if they could pick his brain and to essentially see if there were any loose threads he had in mind for how all of this ends. If anything, it was done out of respect. That Collider article mentions nothing even close to "fixing" anything. Also, I will bet anyone here any amount of money that Lucas didn't direct a Luke Skywalker scene for Episode IX. That doesn't even remotely make sense.