Not really. Under the covers, it has always been an object database where the objects key is the hash of that object, and other than blob, tree, commit and sign

Not really. Under the covers, it has always been an object database where the objects key is the hash of that object, and other than blob, tree, commit and signed tag they haven’t really changed since then. The protocol has become a bit smarter, by allowing there to be additional options passed for different communications options, and there is a slow but steady progress of moving from sha1 to sha256 for the hash function, but that isn’t rolled out yet completely. Different tools have been added over time but the internals are pretty much the same as they’ve always been.