Re: Ahh, Agile -- process fad du jour...
Management fixates on surface details; we must use Jira, have standup, sprint planning, training classes etc. So But they do not grasp the underlying spirit and social messages. They buy the books, read the articles etc. but done read deeply enough. It's sort of like "everyone successful is wearing wide ties so I look successful and so will be successful". I somestimes refer to "cargo cult" management or programming.
Your post is a good example of using appropriate tools and being agile when developing software, use what works. If waterfall works, use it.
And then there is the matter of 2 week sprints. Everyone fixates on that. But to be agile you adjust sprints to the the complexity and organizational friction you encounter. Maybe 3 weeks or 4 weeks or whatever you need.
Remember, agile is an adjective not a noun.