I think they made getting an invite much easier than last year! You seem to forget in your analysis that Nationals will award CP outside of the magic 500. Thus even if you're only at 350 or so, a strong Nats showing can earn you an invite. Couple this with all the different tournaments they host over the year, and I think they've made it slightly easier (even if they did reduce the BFL).
I know I'm excited, since now the total # of tournaments I go to will actually reach close to the maximum number of tournaments that could count (outside of 4 Regionals/States). I might be able to hit up a total combination of 3 regionals/states this year, which would be pretty great and would probably net me an invite to Worlds provided I placed decently well at all the other tournaments and went to as many as I could.