Update:
This was completed on 15 November, 0730 UTC without any issues.

Update:
This has been rescheduled to 15 November, 0730 UTC.

We’re rolling out a few updates to improve the performance of the Unified APIs. During this upgrade, the ability to create or modify Unified Model configurations through the Truto API or the dashboard will be temporarily unavailable.

What’s not impacted

• The /unified and /proxy APIs will continue to function normally, so your customer-facing integrations won’t be affected.
• You can still create new connections.
• The dashboard will remain fully accessible.

So unless you spend a lot of time fiddling around with the Unified Model definitions in Truto, you wouldn't be affected during this upgrade.