I saw that line a different way. Luke acknowledging that he's not sure that Grogu's heart is in it makes Ahsoka think of Anakin because Anakin had a life before the Jedi brought him in - his mother, his friends, Podracing, the whole adventure on Naboo, and continued to have one foot in the other world with Padme, and he frequently considered leaving the order; even Palpatine's temptation, other than saving Padme's life, had a lot to do with Anakin choosing what he wanted to be, not just consigned to be a Jedi.
Grogu isn't so far off from that - probably held as a prisoner after Order 66,then finds someone to love in Mando, and other beings that care about him - a bunch of adventures - and now told you're a Jedi, be serious, you can only act a certain way. Ahsoka is pleased to see that Luke understands this as well, particularly since she herself walked away from the Order because of its limitations and inability to let Jedi be free. Combing the galaxy for any Force-sensitive kid and scooping them up is pretty ****ty.
On a different topic, Luke is telling Grogu all about Yoda - shouldn't he just ask him if he remembers Yoda? They were in the same place at the same time, surely Yoda would have had some at least passing interest in one of the only two other living members of his species.
My brother said the first scene of Grogu and Luke should have been Luke unable to "talk" to Grogu mentally like Ahsoka did, and him completely frazzled, yelling "MY NAME IS LUKE, WHAT IS YOUR NAME?" and getting all agitated.