I think this is more of a general oopsie.They are currently working on Live, which is a timer setting that scales the amount of time you have with unit/city count. This gives a better fast-paced gameplay than 5-minute did since 5 minute was way too long at the start and became very cramped near the late-game.It was originally included in the Diplomacy beta, where it replaced the 5-minute timer but the ultimately decided to delay it a bit while they published Diplomacy. So... My guess is that in temporarily removing it, they just removed the entire thing and didn't add 5-minutes back in.