Insofar as being an actual voice actor, I can see where people would be concerned about Beyoncé not necessarily acting, but just talking like herself; it's a valid criticism and hence why she's not my top pick for the role, since I haven't necessarily seen her in anything where she isn't just "being herself" in a role. (Although I have heard good things about her performance in
Dreamgirls, and I personally don't think she was bad in what I saw of
Epic, though that movie bored me to the point where I was only half-paying attention.) That's not to say that she can't/doesn't go through the proper emotions, but when she talks it's not necessarily always in-character.
When it comes to Nala's actual portrayal attitude-wise, I can see why Favreau was gunning for Beyoncé; when you think about it, outside of being a love interest (which itself was arguably somewhat tacked on in its execution), adult Nala really just exists in the film as someone (living) to kick Simba in the butt and tell him to get off his haunches and go help his pride, and personally the original version didn't/doesn't
quite sell that for me. It's not at all a badly performed scene, but to me when I listen back on their argument, Moira doesn't quite sound as pissed as her animation and dialogue implies. Desperate, pleading, and obviously upset, yes, but not quite as
pissed as I'd think she'd sound. Given that the new film version is likely to go Broadway in giving us more exposure to Nala and the pride's experience under Scar's rule and use that as a springboard into why she ultimately left the Pride Lands, her argument with Simba should certainly have more
oomph than the cartoon iteration. She's grown up under a despotic king, surrounded by enemies in an environment that slowly became something of a hell-scape, presumably with no friends (Scar killed them off if you want to cite scrapped or fanfic ideas); you'd expect to naturally come out of that somewhat hardened or with more of an edge, and in turn possibly seem less forgiving of Simba's seeming lack of motivation to return and help his family. To that end, I can imagine Favreau at least seeing some elements of that in Beyoncé's natural personality, and I'm willing to trust that he's prepared to (and can) direct her accordingly.
To make a slightly greater point, something I've noticed among many more outraged Beyoncé detractors on this project is actually the same thing I've noticed in criticisms/complaints about Gabrielle Union's portrayal and even some stage versions of Nala, and that is that they feel that Nala isn't portrayed as "sweet and petite" as the original. Now, this doesn't really apply to anything I've seen here, but these comments are certainly in the vein of this general stigma surrounding black women that they are "too forward" or "aggressive" and not "gentle enough", even if the statement is based on little more than vocal quality. (All of these are phrases I've seen used in comment sections of Facebook and other social media posts.) I found it especially telling when I came across an article last week regarding Union's new autobiography; in the interview about the book, she mentions her
Lion Guard gig and briefly mentions that she was occasionally told by the producers that she was delivering her lines in a manner that to them was "too angry". The interview doesn't go too much further into the details - I assume she elaborates on it a little bit more in the book - or say what the lines were in question, but I can't help but think it plays somewhat into this general backlash against black actresses in acting/speaking roles (particularly when they're relatively deeper-voiced) and particularly when it's someone like Beyoncé, who in a lot of ways is many peoples' embodiment of everything they don't like/fear about black women, and then amplified x10 because of her stardom, especially after her Superbowl "Formation" performance last year. (Perfectly typified in the
Saturday Night Live skit, "The Day Beyoncé Turned Black":
https://www.youtube.com/watch?v=ociMBfkDG1w) Again, not saying it's anything that exists here, but I know it's a sentiment that exists "out in the world" and I'm sure it's part of why many people aren't fans of Nala's new voice.
(There are also people negatively freaking out about the racial makeup of the cast and using Beyoncé as the emblem for why it's bad.)