I don't think Shanks cares about Freedom at all actually, it's just peace.
However, I think the method of which he's trying to achieve this will be flawed. I've always looked at Shanks and Blackbeard as Order and Chaos. There is a reason he can talk to Gorosei. There is a reason he knows about Nika and the Gomu Fruit. There is also a reason why he seemingly chose Luffy for this task of being Nika. Some part of his motive comes from believing Luffy will do the right thing as a pirate, liberating countries from tyrannical pirates especially, i.e. the Warrior of Liberation, Nika.
But I think that's where the line is drawn. Imo, Shanks is certainly using Luffy to essentially control the world. So while he liberates pirates from control, Shanks essentially wants to control the world as a basis to achieve peace. He cares about Luffy of course, but there's definitely some underlying motive here. I'm sure some of it has to do with Roger and Rocks. I'm sure it'll involve One Piece, Ancient Weapons, and the WG National Treasure. I'm also sure it'll involve Laugh Tale, Mariejois, and God Valley, probably the 3 most important locations in the series at this point.
So whatever he's doing, it's just complex and not that simple to explain. I think "freedom" comes at the result of this idea of peace, and this is where he and Luffy will disagree.