Thanks for writing in! Both classic and V2 elements offer certain value proposition. On one hand, V2 elements gives you more flexibility regarding customization without the need of CSS. On the other hand, classic elements are quite simple to use but don't offer much of GUI based options in terms of styling the elements and more often then not you will have to write some CSS to make changes. That being said, we are not going to disable the classic elements.
If someone has used classic elements in the past, they are free to continue using classic elements. However, if they want more flexibility then they can take advantage of V2 elements.
One major difference is that, classic elements will follow the theme option settings, so you can control all the common settings in one place. V2 elements does not follow the theme options or global defaults because it has its own independent default settings. You may apply presets or tweak the v2 elements settings if you want to change something.
To get started with V2 elements, I suggest you to please take a look at our KB section.
I am sharing few more resources that you can take a look to get started with V2 elements.
Hope that helps.