2D animation industry standard is Toonboom currently. There are some that still use Flash for Pre-production, and fewer still that hold on to Flash/Adobe Animate, but it's being phased out.
Having said that, it's still a good program to practice the fundamentals of animation, because it is quick. Even though it does have its problems, and gets a little crash-happy.
Additionally, I did hear about a prominently 3D animation software company, possibly Blender (I'm not 100% certain), is rolling out with a 2D competitor in the field. Last I heard it was still in beta, but keep your eyes peeled for murmurs about studios using that.
A good way to double check to stay updated on the industry demand for software experience is to browse through Artstation
https://www.artstation.com/jobs
These companies will tell you what they're looking for in experience when they post job listings.