OP writes "retcon the characters progression from the first movie", which I read as the character being put in front of the same obstacles they had to overcome originally, or regress in whatever way they evolved in the first movie, or something like that.

The family ties thing does nothing like that. Luke still has his force powers. He does get to do the training with Yoda, which is arguably similar to his training with Obi-Wan, but it's not like he's starting from from scratch again. He just needs to level up to have a shot at taking on Vader.