This is how the presuppositions work.
There is no even partly feasable reason for Willi to ever return to Wollust!
Python:
d "Leia."
mi "If I remember correctly, she was your sister?"
d "No. We grew up in the same household, but we're not related."
d "At one point we had a bond I'd describe as much closer than family."
The reason is named: the bond which is much closer than family. You just don't like it. But it's feasible enough and makes the story roll.
One might ask, why then he didn't return earlier if the bond was so close? Well, do you know, what Helen said him in the prison? Maybe him, staying away from Zanes was the condition the Families let him live. An important peice of story isn't revealed yet.
He would never crawl back to and for Helen, a person which hurt and betrayed him so much as the new storyline shows.
Yep. Or maybe she saved him because the condition of him staying alive was that he serve his time in prison as punishment. Maybe he was framed because that was the punishment the Families had arranged? Maybe Helen's visit was a guarantee that he understood the conditions and agreed to them and there was nothing she could do for him?
BTW, we were just talking with RNasc about the Banshee series, it's literally the same trope, there the MC was framed and put into prison by his boss, because he "seduced" his daughter and was about to run away with her and the diamonds stolen from the boss. And the boss made sure that his "vacation" in the prison will be quite unpleasant.
I think, I recall from old WiAB something about Willie got beaten in the prison almost all the time, and his panic fear of returning to the prison again, right?
Betrayed and hurt... Well, that's just one possible interpretation of why she did it.
Willi and Leia two kids they only raise for later profits, they do not even like them. The first or second time the siblings would really harrass Kati the two would live through a blue wonder of punishment. Afterwards the two would never even look strangely at Kati again.
Python:
mi "It sounds dangerous. What if they don't exile you and instead go for a more permanent solution?"
d "Nah, as much pain as I caused everyone here... They love me, and I don't think they can afford to lose Leia."
Willie belives that they love him at least.
And even this short "sweet family memory" of him fighting with Leia under Dylan's supervision hints that the Zanes didn't let their children grow up weak. So maybe they encouraged Katie to stand up for herself and not get involved in their squabbles. However, if you remember, Willie got punishments for bullying Katie, for example, when they locked her in Gina's cafe. He himself recalled that he was grounded for a month or something like that. Quite an adequate punishment from parents who do not differentiate between their own and foster children.
The Zanes are all now hardcore criminals and Willi, who grew up there, is completely baffled by this, another plothole big as a SUV.
So before Dylan was a mechanic and Helen was a housewife right? And who was uncle Joe? Did Joe and Dylan have some common business? Who was Leia before? Why do I have a feeling that plothole, that was before is patched now.
Anyway, to each their own. You don't like the changes, I didn't like the old version. Only time will tell if the new version will be succeeded.