Why didnt they let Bill be happy. He should have been able to continue dating Kahn's mom.
We don't know if he did. She went to a home, didn't she? Who knows where the home was. The passage of time in this show is arbitrary at best. Perhaps, in the end, the end of the relationship was a mutual one!
In the episode directly after this one he mentions them dating when Bobby reads his fortune via tarot cards. She is then never mentioned again until s10 where she is used for tips in exchange for the newspaper's weekly crossword puzzle answers.
No mention of their relationship ever again. And it being Bill I feel if he breaks up with someone there's gonna be an episode about it.
The reason as to why we never hear from her except in passing mention or over the phone is because the lack of story driven episodes. We vaguely get some with Lucky, in fact id say the stuff with Luanne and Lucky dating then getting married and having a kid are the closest things to consistency after season 6, but it's pushed to b plots mostly.
This KILLED me especially when a single line about her moving back to laos or something could have resolved it… and then when Bill dates the reverend he breaks up with her immediately because “the magic was gone” after she moved in as if everything we’ve learned about him up to that point didn’t suggest he would stay even in an abusive relationship bc he’s so desperately lonely?? They did Bill so bad… the closest we got to him finding long term happiness was when he realized he doesn’t really want kids but even that felt like it was just meant to get him back to status quo :(