No. Why would the white iPhone 4 be produced until June 2012 in both sizes? They're just putting that date in arbitrarily because that's a year from this coming iPhone 5's launch (roughly).
If Apple keeps producing a white iPhone 4 as the "cheap" model it will probably be an 8GB or a 16GB model, much like the 3GS.
Plus, why do you need this to be "confirmed"? Everybody knows that Apple sticks to a one-year release cycle for the iPhone and it is pretty obvious that the 5 will come in late June of 2011, and the 6 in late June of 2012, et cetera.
Fairly straightforward.