I think that is a rather common belief... "Managed" is exactly referring to automatic memory management meaning the defining feature of the category is literally GC.
Wikipedia disagrees. "Managed code is computer program source code that requires and will execute only under the management of a Common Language Runtime virtual machine, typically the .NET Framework, or Mono. The term was coined by Microsoft."
Huh. By that definition Java isn't managed, which seems to be missing the point and not as nearly useful as a broad category like everyone outside the Microsoft ecosystem uses it. That said, even if "CLR" is sensibly replaced with "CLR, JVM or similar", it does seem like I have the etymology/definition wrong, thanks.