I have worked on a combination of Time boxed and CD. The timeboxed ones had a overarching timeframe defined but we had lot of leeway within that to go and do our thing - sometimes we would spend more time thinking about how to solve it more efficiently - do PoCs, brainstorms and that saved us implementation time. We would have weekly status update meetings and more if needed - it was mostly self organizing and so long as we had people that cared and knew what they were doing it really worked well.

The CD ones were ones that actually needed continuous work - lots of new code needing routine bug fixes, Security fixes, artifact updates, incremental devops/automation for legacy projects etc.

He's not complaining about Agile itself.

He's complaining of the non-Agile practices that became synonymous with Agile, eg. Scrum, thanks to Agile coaches that feared losing power.

He must've used some kind of work planning and scheduling though, even if it was 'as soon as possible but not sooner'