I'm not sure. Time is obviously passing him, however looking at the future sites:
Next two British Opens are at Hoylake and St. Andrews. He has won at each. It then goes to Royal Troon.
Next few US Opens include Pinehurst and Oakmont, with 2 other courses who have never hosted the US Open previously.
Next few PGA's include: Oak Hill this year, Valhalla (Tiger has won here), Whistling Straits and Baltrusrol, all courses tiger has experience at.
And of course, while Tiger hasn't played particularly well at the lengthened and narrower Masters, he has been in the hunt a few times.
If Tiger has his game on for even 50% of these, he could knock out 2-3 majors, maybe more, maybe less, maybe none. But I'm not going to wrote him off just yet.