If it was not subjected to heat, it might do very well. I had lots of 9x12 sheets of (cold stored) Tmax 100 left over from a past job - by the last sheets they were eleven years expired, and there was only are tiny difference in sensitivity and base fog across the entire time, in spite of sticking to box speed throughout.
YMMV - 400 might age a bit worse, yours is almost twice the age, and unknown storage conditions might have killed it. Under these circumstances I would not buy a entire crate blindly - but if you can try a box first, do so, there is a fair chance that still does better than the bottom range cheap films on the market...
