I'm quite excited for this, but don't get your hopes up too much.
The main rumor and speculation at this point is they are just finishing the Legacy stories they made.
Which if you check this link and do some digging lines up quite accurately. https://www.starwars.com/tv-shows/the-clone-wars-legacy
The very first episode in that link lines up perfectly with the Trailer that has been release with Rex, Anakin and the Bad Batch Leader.
This is the "Cheapest" move for Disney to make a few bucks. They have the stock reels and voice acting all done.
All they need is the "Special Effect" magic.
The site alone has 8 episodes which covers 2 arcs. So all Disney has to do is come up with 4 episode of their "own". Which we all know and saw in the trailer was Mandalore.
As for what it means for the future of the Clone Wars. We will have to wait and see.
Also note. If I'm right on this and you wish not the episodes to be spoiled for you. I suggest on not watching the reels in the link I gave. They are fully completed episodes with story and everything. They just haven't done the final "Movie Magic".
So we might have already seen most of the "New" Clone Wars already.
Don't get me wrong. I'm not saying it is a bad thing. I love the episodes and would love to see them in their completed state. I'm just warning you guys so long to not get your hopes up too high for this.