With my cynic hat on I think they're being forced by larger strategy. The existing Freebase dumps are far too useful for a Google would be competitor, and I suspect the Knowledge Graph API will be somewhat more restrictive in what you're allowed to do with it.
The thing is the more you get into this stuff the more you envy Facebook's position where people give them structured data on a plate.
from the article:
> The last Freebase data dump will remain available
and even if it wasn't, I'm sure archive.org will grab a copy (if they haven't already).
Say you're using it to get a list of named entities (proper nouns). The purpose is to cluster news stories about a given entity (if you look at Facebook's Trending News, each headline begins with a proper noun followed by a blurb. Not sure if they use Freebase, but it could be a useful input).
The value of Freebase will decline over time as the content becomes out of date.
Wikidata RDF exports are made every two months or so from those dumps and are available at [2]. I imagine that frequency will pick up. You can generate your own RDF exports using the Wikidata Toolkit [3, 4].
[1] http://dumps.wikimedia.org/other/wikidata/
[2] http://tools.wmflabs.org/wikidata-exports/rdf/
Do they get any structured data other than user profiles?