Taliban statement on negotiations poses questions

Has the Taliban modified its negotiating stance in relation to the withdrawal of foreign troops? It has always stated its implacable hatred towards the ISAF forces and pledged to continue fighting until all foreign troops are withdrawn. But a statement issued today by the Taliban presents what could be considered a softened line. The statement, called Known Figureheads and the Futile Reconciliation Slogans, is a diatribe against President Karzai's High Peace Council, which is described, predictably, as an American pawn. However, the statement continues:
"The reconciliation propaganda launched by the Americans and the Kabul Puppet Administration is meaningless in the light of this hard fact that how can reconciliation be materialized in condition of presence of more than 100,000 foreign troops, being armed with motley of weapons, aircrafts, missiles, tanks and other warfare hardware.
"The rationale for reconciliation can be only convincing when, at least, the invading Americans put signature on a document before the people of Afghanistan and the world, binding them legally to withdraw their forces from Afghanistan in a given time-frame.
"This is necessary because the Kabul mercenary government has signed various agreements with the Americans which allow them to keep their troops stationed in Afghanistan for tens of years."
I have not seen the Taliban leadership argue this before. It appears they are saying that they would be willing to talk about reconciliation with the Karzai regime provided the USA agreed to withdraw from Afghanistan on a publicly-stated date. Previously, the Taliban has always made it clear that negotiations could not start until after the withdrawal of troops. Unless this is a careless translation, it looks to me like a small, but significant change.