You have to keep in mind that currently curation is non-linear so the front running of big votes is still in play. The linearity only applies to the payout distribution of the posts but not to how the curation rewards are allocated to each voter.
I am not a blogger so 90% of my income depends on curation. If the EIP is approved it's important to me to know how it will playout but currently I can't visualize it...will there be less people posting or more? Will the competition for curation rewards get tougher or the opposite? Difficult to say.
One thing is sure, there will be less social interaction on posts. Now you need about 800 SP for a single up vote on a comment to exceed dust level, and that 800 SP up vote should get the commenter 1.5 ct. After HF21, most likely you'll need 1600 SP for a single up vote to exceed dust level, and that 1600 SP upvote will only get the commenter 1ct.
It depends on the shape of the curve. If the linear portion starts too high then that would be the outcome but the proposal is not set in stone yet.