The Big Bang Theory Deleting Leonard's Love Is Wrong
The Big Bang Theory that deleted Leonard's love interest did damage the arcs of at least 3 characters, Leslie Winkle herself being one of them.
As one of The Big Bang Theory's original characters, it would be a mistake for Leslie Winkle to be removed after becoming Leonard's lover, given her impact on the show's overall narrative. Mainly spending time with Leonard led to an affair that eventually disappeared. The Big Bang Theory tried to include her in other ways, but despite being an interesting character in her own right, she ended up receding into the background until she was fully written. While removing her from the show made sense for Leonard's narrative moving forward with other romantic partners, Leslie could have stayed on The Big Bang Theory for a different reason.
CBS made sure to compare Leslie and Leonard; they mirror each other and even dress the same. Given their romance, she was expected to be part of the Pasadena gang. So, when Leslie Winkle faded from TBBT, people were confused. According to Jessica Radloff's book "The Big Bang Theory: The Definitive Inside Story Of The Epic Hit Series," the character was written to focus more on Leonard's relationship with Penny's burgeoning relationship. While that's understandable given the pair's popularity, getting rid of Leslie would be a mistake.
Removing Leslie On TBBT Was Wrong Because She Challenged Sheldon
While Leslie's relationship with Leonard was going nowhere, The Big Bang Theory could have relied on her rivalry with Sheldon to use her in a different, arguably better way. In this nerd-centric sitcom, Sheldon develops a loathing for Leslie because not only is she potentially as smart as she is, but she won't let his bad behavior go unpunished. Leslie would call him out when he made a mistake, usually in the harshest possible way. So, while Sheldon's friends tolerate him on TBBT, Leslie always puts him in his place. It will be interesting to see more of this dynamic.
Somehow, Leslie and Sheldon's dynamic is reminiscent of the socially incompetent genius in Young Sheldon's initial relationship with Page. Like Sheldon, Paige is a prodigy, maybe even smarter than him. Besides that, she's more emotionally and socially capable than Sheldon. While it annoys him, dealing with someone like Paige is a great teaching experience for Sheldon — and The Big Bang Theory can do the same for Leslie.
What Happened To Leslie On The Big Bang Theory
Leslie Winkle promoted to regular on The Big Bang Theory Theory season 2, but CBS started using her less after her less serious romance with Howard. She was last seen at Sheldon's surprise birthday party in Season 9. While Sheldon and Amy's Nobel Prize in Physics was a big moment for Caltech, Leslie wasn't in the Big Bang Theory finale, and she may have found a different job . Otherwise, it would be meaningless for her not to participate in the celebration. Perhaps CBS can clarify what happened to her through Sheldon Jr.'s account.