I wasn't there for the conversation, but as written that sounds like a bit of a leap. The choices the writers had Laurel make were a big part of why I thought she was just all right, as was her being a legacy character following my favorite, but I also thought Cassidy didn't handle the emotional turmoil elements of the character well and that exacerbated the writing. She was better at the beginning and the end when Laurel was relaxed, confident, and generally happy because that played more to Katie's strengths.
I consider Willa one of the better actors on the show. One thing I like about her performance is that she's Moira's daughter; she's more relaxed and warm, but she has some of the same regal bearing, and it gives her a sense of emotional maturity that her elders often lack.
Well, to each their own; I thought Cassidy did well with the role, as did my family. She just didn't have great material to work with, and therein lies the problem, not her performance.
I'll agree that Willa adds regality and uppity attitude (not in a bad way) to her performance, in honor of Moira, and it's very effective. She does deserve credit for her performances, but sometimes she feels a little one-note (her angry-voice is always exactly the same: enunciate the last two words of her sentence with a snarl). But overall, yes, she's very good.
I'd thought of another way Laurel could've been used more effectively (and this is just my opinion); I'm eager to see what thoughts other fans have (looking at you especially, Primal Slayer and Slade Wilson). My thought is, when Laurel revived Sara, rather than have Sara join LOT and Laurel remain behind, have it be the reverse: Laurel joins the LOT crew, and Sara takes her place on Arrowbut before leaving, Laurel inspires Sara to take up the White Canary banner.
Here's why I have this opinion: first of all, it saves Laurel's life. Secondly, I'd
dare Guggenheim to kill off his precious pet Sara. My guess would be, Lance would die in Laurel's place in this scenario. It would serve as motivation for Sara and Oliver the rest of the season, and then when Laurel returned in the season finale of LOT, she'd have the same reaction that Sara had when she talked to Lance and found out about Laurel in the season finale. And then, when she demands Rip take them back (like Sara did when she wanted to save Laurel), Rip would reveal the truth: he knew that it would be Laurel who died at Damien Darhk's hand in 2016, so he took her away to prevent that. It's as effective, at least, as the revelation to Sara in the season finale, and it allows Laurel and Sara to both survive. And then, Laurel could leave the LOT crew and return to Arrow; Sara could remain on the show or leave like Thea and Diggle did. Anyway, it's not a complete outline like Primal Slayer's idea, but it's a start (and I think the Laurel/Rip conversation when he reveals that he saved her because he knew she'd die would be way more emotional than the similar reveal to Sara).