At first glance, expecting Catholics to abandon Ash Wednesday to accept Ash Monday or Ash Sunday or whatever, seems impossible. But then considering how many other long-held traditions have been given up overnight, one can't presume to know what nonsense Catholics will endure in the future.
Wait and see, and don't be too surprised come what may.
The important thing is to know what the tradition is based on so you can know why and when to resist the novelties.
If Bergoglio and his bishops announce that henceforth, Easter is the third Sunday of April and Ash Wednesday will be transferred to the prior Sunday (they won't change it to Monday), the Novus Ordo community will accept it, no questions asked. In fact, many Conciliar apologists (e.g., EWTN, Catholic Answers, etc.) will praise the change with, "It's about time the Church fixed this problem."
The Indult community is another question. They may or may not go with the change. In the Indianapolis archdiocese, the Indult parish retains the 1962 calendar's date for the Feast of Christ the King while the Novus Ordo uses the new date for the Feast of Christ the King. It is possible that the Indult will use the traditional date while the Novus Ordo uses the new "fixed" date.
The R&R community will use the traditional date if the Indult community does so. What they will do if the Indult community uses the new "fixed" date is not something that, I think, anyone can know until (or if) it happens.
Catholics, on the other hand, will reject the novelty.