Google Deployment Manager has a --preview flag on updates that surfaces a similar preview object.
Crossplane validates through Kubernetes admission controllers, which is a different shape entirely: the check happens at API server time, before the composition ever reconciles.
The honest read: AWS closed one of the gaps that made CloudFormation feel a step behind newer IaC tooling, without asking you to change how you deploy. The default path is now the safer path, and for most teams the default path is the one they actually use.
What I am watching next
Two things. Whether AWS extends the WARN tier into direct CreateStack and UpdateStack, because the current split is the sharpest edge in the release. And whether cdk validate becomes a primitive other tools can invoke, so that a pre-commit hook in a monorepo can call it without spinning up a full synth pipeline. If you try it on your own stacks this week, I would love to hear where it caught you, and where it politely did not.