Could be. Most projects I've worked on tend to span multiple services though, so I think AI would struggle more trying to understand and coordinate across all those services versus having all the logic in a single deployable instance.
The way I see feature development in the future is, PM creates a dev cluster (also much easier with a monolith), has AI implement a bunch of features to spec, AI provides some feedback and gets input on anywhere it might conflict with existing functionality, whether eventual consistency is okay, which pieces are performance criticial, etc., and provides the implementation, a bunch of tests for review, and errata about where to find observability data, design decisions considered and chosen, etc. PM does some manual testing across various personas and products (along with PMs from those teams), has AI add feature flags, launches. The feature flag rollout ends up being the long-pole, since generally the product team needs to monitor usage data for some time before increasing the rollout percentage.
So I see that kind of workflow as being a lot easier in a monolithic service. Granted, that's a few years down the road though, before we have AI reliable enough to do that kind of work.