No, it does not mean that. It means that the node has to send less data with graphene. The block, when reconstructed, must contain all the data, and must fit into the LIMIT.
I think you don;t understand what Graphene is used for. It has nothing to do with Fees or blockspace. Fees and Blocks will be the same. What Graphene does is make it faster for miners
to propagate blocks to other nodes. The idea is that most active nodes have mostly the same TXs in their mempool. With Graphene, when you receive a block, you don;t need to download
the full block. Nodes with Graphene activated don;t need to receive the full block. They just get the header and a couple other things and recreate the block using the mempool
that their node already has. The size of the block is the same, the size of TXs is the same, nothing changes on that front. What changes is the way your node receives the block.
The chart you are talking about is talking about the information that the nodes send between each other. The idea is that you don;t have to dwl 100% of a new block.You just recreate it
using the mempool your node already has. Because active nodes have a similar mempool, you just get the block header and some Graphene Information related to the TXs. Then your node
(using it's own mempool) recreated the block that was sent using Graphene. It is important for you to understand that this has nothing to do with Fees, Blocksize or LN.
If you have a node with 30mb of TXs ( all of them different Size, paying different fees and whatnot) and you get a new block that is 28mb in size, Graphene help your node by not having
to re-download those 28mb because you already have that information in your mempool. With graphene you just send some information about what TXs are included in those 28mb. So you only
receive a packet of 0.5mb with Graphene. Do you see what I mean? In the end the blocksize ( written to HDD) will be 28mb, the TXs will have paid whatever fees they wanted, but this is
not what Graphene is about. Graphene help nodes communicate blocks faster because most of them have the same mempool of TXs. So you don't have to re-download all the TXs in the block.