Good heavens, no! Way too much risk that I would:
a) change my mind about using those fabrics,
b) change my mind about ever wanting to make that project at all,
c) decide I really wanted to use those fabrics for that other project, or
d) all of the above.
I'm an intuitive quilter, often working on impulse alone. Cutting up fabric for something that isn't happening 'right here and right now' just doesn't work for me. To each our own, right?