Cynically, I wonder if this policy change was not prompted by Kickstarter's own doubts about the lifx team being able to deliver. After all, this is the same team that couldn't meet demand for their custom cardboard box project.
I wonder if in the future there will be a requirement to limit the number of backers on every project. Logically there seems to be a point where additional money from backers over what was asked for leads to difficulty delivering at all.
For instance, say I could make 10 custom widgets a month at $100 a piece. I might decide to launch a Kickstarter project asking for $1200 to gauge if at least 10 other people are interested in my fancy innovative widget. What happens if I end up raising $12000? My target of 20% profit on each widget is no longer possible unless the backers are willing to wait up to 10 months for me to deliver. The only other option is to invest money into producing widgets in larger volume to meet this initial demand. That investment would only make sense if there were some reasonable expectation that demand would stay at the same level after the Kickstarter project ended.
So back to my original cynicism, maybe Kickstarter sees signs that some very good marketers are having enormous success with Kickstarter projects whilst being in completely over their heads...