If I Hidden Blade an enemy minion but there's a hidden Zhonyas so it's activated does the enemy still draw 2?

Yes, the controller of the targeted unit will still draw 2 cards.

According to RiftJudge FAQ #10456 and RiftJudge FAQ #5700, when Hidden Blade resolves, it checks if its target is still a legal target on the battlefield. Because Zhonya's Hourglass acts as a replacement effect that intercedes during the resolution of the spell (replacing the "kill" event with "heal, exhaust, and recall"), the unit remains a valid referent on the battlefield at the moment the spell begins to resolve. Since the spell successfully resolves and identifies the controller of that unit, the draw effect still occurs.

Sequence of Events

1. Hidden Blade is played, targeting a unit on the battlefield.
2. Hidden Blade begins to resolve.
3. Zhonya's Hourglass's replacement effect triggers, replacing the "kill" event with "heal, exhaust, and recall."
4. Because the unit was a legal target on the battlefield when Hidden Blade began resolving, the spell successfully completes its resolution.
5. The controller of the unit draws 2 cards.