A curious thing about the new icon: because it feels more casual, I've been tapping on it more often. It's certainly bold on my screen, compared to many other simple icons on white. I think with the previous icon, it had a feeling of a utility or tool, almost like it might require work to interact with.

The camera icon in the actual tab bar is also reduced a lot now, and one could argue that they no longer have to encourage content creation: the argument is already made.

Despite how long this branding lasts or what's to come, I think Instagram is actually on to something relevant for the brand as it exists today, in my opinion.