wizaerd - most parts of the engine do not have fixed limits. Nothing you mentioned (number of objects, number of sprite animations, number of sprites) have any fixed limit - you can keep going until you run out of memory.
The code snippets you posted refer to particular details of the WebGL renderer. It renders objects in batches for efficiency, and that code simply means it will draw a maximum of about 2500 objects per batch. If you have over 2500 objects, it will just send multiple batches per frame and keep going just fine.