What the tempco -is-, and what the tempco
"could be and still get shipped" are loosely related.
The latter pertains to WCA but isn't going to tell
you anything about one piece in hand necessarily.
Other than, it should be better (how much, is not
said unless you paid for detailed test data pack
which is not really an option outside MIL / aerospace
product grades with their heinous pricing, to which
the data pack is always another lot based upcharge).
Some sensors have nonlinearity (bowing) which
will make an end-end tempco lower than tempco
measured near either end and higher than in the
middle.