Earlier quoted context omitted.
Premature optimization may hit them hard. Overengineering is imo usually the bigger technical debt and a huge upfront cost as well. Well-thought out plans tend to become a sunken cost fallacy. Making room for changes is hard enough in XP like ways of working. When you have to tell your manager that half a year of careful plans and engineering can be thrown away, because of the new requirements, which emerge from late…
Infra should not require much in the way of redoing if it's done correctly. Foundational software's configuration like RDBMS schema, maybe, but I wouldn't classify that as infra per se. Seriously, I'm struggling to figure out how "we have servers that run containers / applications" would need to be redone just because the application changed.
I would always recommend "serverless" monolith first with the option to develop with mocks locally/offline. That's imo the best risk/effort ratio.