I'm not 100% sure about this, but after some fast tests it looks like it's the case.
Have to say I personally don't have autosave replays enabled for myself, so I'm writing this according the feedback from others.
A Story follows:
Not so long time ago, i was running a server with gamemode 0 and the TimeAttack.Script.txt defined, and during the same day i got 2-3 people saying:
I was like:What have you done with the server here.. it doesn't save replays.
Until I figured it might be the new scripted game modes actually, then I fastly switched to legacy game modes and people was getting auto save replays again or at least nobody was saying they didn't get the replaysWhat? If I press S, I surely saves the replay.. or is it some automatically thingy.. could it be the value: "autosave replays" in dedicated server options?

Best regards,
Reaby