Let Cardinal Castrillon-Hoyos be clear to you:
Cardinal Dario Castrillon-Hoyos-- the president of the Ecclesia Dei commission, which supervises Vatican outreach to traditionalist Catholics-- says that "from this point, priests can decide to celebrate the Mass using the old rite,
Right and it is clear to any one reading the MP that this is only in the case of a private, or semi-private, celebration of the Extraordinary Form. It explicitly states that any private celebration must be done with the guidance of the bishop.
Nice how this is ignored by many. The Cardinal does not say that public celebration can be done with out the bishop, only that the priest is free to celebrate the EF and when one takes that statement and actually reads the MP they see that it applies to private, or semi-private, celebrations not public ones.
If one takes your point and runs with it then we can also say that the Cardinal is saying that a priest may celebrate the EF during the Easter Triduum which when we read the MP we see that this is not so.