It seems to fall into the "too little, too late" category: the benefits it brings are not massive due to my three points above, and the disruption introduced to the ecosystem is potential massive.
I agree that it is too little. There is a lot of brain damage in the prelude that really should be fixed. I don't think its too late though, we can start making forward progress with changes like this. Yes we need many more, but I think there is hope for redemption. We will want to work on our approaches to the upgrade path but several good ideas have already been put forward and tooling can be improved for the people who insist on long backwards compatibility periods. Personally, I'd like to see a cleanup of each section of the prelude, its seriously holding us back.