There are constant internal updates, the most recent was two days ago and several more before that. We don't announce such updates, as they do not bring new features, but they are utterly important as we fix various performance and speed issues, improve reliability.
We don't want to pump it with features and make it slow and unreliable. Quality over quantity.
It's also not possible to roll out updates every 5-7 days like in the first days, as user base had grown significantly so there's much more responsibility. Every update needs to be carefully tested, and updates that require server restart are being accumulated so that restarts are not too often.