I heard somewhere that he had equipment in his bag from seven different manufacturers, so he is picking and choosing what works best for him. Probably only he and the folks at Callaway know why he is no longer on staff.
From GolfDigest WitB:
What Patrick Reed had in the bag at the Masters
Ball: Titleist Pro V1
Driver: Ping G400 LST (Aldila Rogue Silver 125MSI 70-X), 9.2 degrees
3-wood: Nike VR Pro, 15 degrees
Irons (3): Titleist 716 T-MB; (4): Callaway X Forged 13; (5-PW): Callaway MB1
Wedges: Artisan Golf (51, 56 degrees); Titleist Vokey SM5 (61 degrees)
Putter: Odyssey White Hot 3
I know most of us have our Callaway pom-poms out, hoping the winner plays Callaway, but... he played with Callaway irons and an Odyssey putter. But it came down (in my opinion) to what made him comfortable and gave him confidence. One club does not fit all.