I've never read with Mattie before but I will say that no matter what reader I've read with, the readings nearly always take years to unfold for me outside of a few very minor things.
Readings with Kisha have taken 3 or more years to unfold, still waiting on a few readings to unfold from 4 years ago, 3 years ago, and 2 years ago.
My one reading with Yona took 3 years to fully unfold.
My readings with Sincerity are taking nearly two years to unfold but to be fair my timelines were initially already predicted for further out in the future (years).
So, anything is possible. I definitely wouldn't hold on though.