Today Moshi Monsters have said that quests will return soon! Check out the email I recieved:
If you can’t read that, there’s this:
Thank you for your email. I see that you’ve noticed that the Quests have temporarily vanished from the streets! Looks like all the Monster Owners did a super-great job in helping out all the Monstro City Citizens! Don’t worry, I’m sure the Quests will be back soon. It looks like no one needs any immediate assistance at this time. Keep an eye out though, they’re sure to be back!