Over in the Classic Update thread, this caused us to do some investigation:

Classic Update I believe it is still incorrect to say that warlock pets despawned immediately upon a new summon beginning to be cast. The Debuff “Summoning Disorientation” is supposed to take effect on the existing demon for the duration of the summon cast. If the cast is interrupted or stopped. The original demon is supposed to become unstunned and available for continued use. There are no patch notes showing this was ever added or changed, documented or undocumented. Kaivax please check and see if the debuff “Summoning Disorientation” existed in the old codes. If so, then that is the reason for the discrepancy between what players remember, and what the old code says. The missing piece if you will.

I can tell you – it was fairly straightforward to find the answer to this one.

Summoning Disorientation is spell ID 32752, and that alone tells us almost exactly when the spell was first built. New spells are added sequentially.

This spell was built for version 2.0.1 of World of Warcraft. Also, we can look at our original version 1.12 and see if it it was there. It was not to be found in 1.12.

I’ve noticed that my memories of the game sometimes don’t line up with reality, and it’s quite valuable for us to have the original data and code from that time period to reference.

Thank you for pointing us in the right direction.