So I accidentally waited in the NCR embassy at night while Crocker wasn't in the building, and now he won't show up. Awesome! Who doesn't love doing arbitrary things that end up breaking the game! If I load a previous save and delete all the saves after I waited in the embassy, will he reappear?

You sure he isn't sleeping in like another room or something?

Where else would he be other than the embassy? I checked the MP heardquarters too.
I also waited until it was a different day, time, etc. he's not just sleeping.

Wikia entry:
"If the Courier waits in the Embassy at night when Ambassador Crocker isn't around, waiting for him to appear in the morning/afternoon, he will not appear in the building. All you have to do is take your player and exit the Embassy and re-enter for the Ambassador and his secretary to appear in the Embassy. He will not always reappear though, sometimes disappearing from the game permanently."

Maybe he's gone for good?
Bah, screw Crocker, go to Caesar instead.

Yeah I know he's gone for good, I was asking if there was a way to make the game forget I ever waited in the embassy, by deleting the save or something. Also, I think I should mention that right after I glitched Crocker, I went to Red Rock Canyon to mess around, and it turns out I rendered the quest Oh My Papa unstartable because I DARED to talk to Regis before Papa Khan. LOL how do these developers have a job? Unbelievable incompetence to let this kind of thing happen routinely, even AFTER a patch. At this point, I'm scared to do anything for fear of breaking some quest.
"You shot a cazador in the wing and then the head with a 9MM pistol while Lily and ED-E were your companions and Lily had 217 pounds of equipment on her? Looks like the Brotherhood of Steel bunker won't open for you now."
Unbelievable.

To answer your question, no, deleting any saves wouldn't rectify anything.

But if you play on PC, did you try console commands?