it looks like they're hinting towards offering a 'self-hosted' model

That makes sense. Datadog has been pure SaaS the whole time, which is unusual. Buying a good db engine like Quickwit would be a smart head-start into the on-prem segment which is a natural expansion opportunity.

I've previously made the prediction that Datadog is the new Cisco - can expect lots of acquisitions to be made going forward.