NYS Thruway History

The NYS Thruway has a bunch of exits that connect directly to other
freeways. I know some of these connected to other local roads before
their freeways were built. However, the thruway has some exits with no
obvious former connections to other local roads, specifically exit 36
(I-81), exit 39 (I-690), exit 50 (i-290) and exit 53 (I-190). Were
these exit numbers left out until their freeways were built, or did
these exits exist before the freeways and connect to other local
roads?

-Dan