Let me just make a tweak to your problematic phrase by suggesting that its components, “metadata” and “infrastructure”, by themselves are fine if used as technical jargon. Metadata has a precise denotation of data about data and an equally precise connotation that under most circumstances such data is inert, it should not alter the normal function of an application one way or another. Or, perhaps, that if it does affect function, it does so through metaprogramming, or dynamic programming techniques, as with some examples of Java’s annotations and Python’s analogous language feature, decorators.
So it goes for infrastructure, that this is the basic operational framework on which an application relies. Pithier than constantly referring to operating system, database server, web server, web server modules, code frameworks, etc. expansively when referring to a some aspect of these necessary pieces outside of actual application code.
That being said, the need for such technical precision is dependent on the presence of potential ambiguity in a discussion. I agree that even in technical conversations simpler, less precise terms will often due when there is no ambiguity, no possibility of a mistake because two techies thought different things on hearing the same, fuzzier term. In a context where such ambiguities exist, the more precise jargon ensures that everyone is on the same page.
There is a cost to using technical jargon correctly, too, that has to be considered. Techies working together have to make sure that their definitions and understandings of these terms match. There is obviously a risk if they do not, which can easily be hidden by an over reliance or too much confidence in the arbitrary precision of the terms themselves.
Sadly, while I picked this small bone of contention, I think there is a corollary even among more technical circles. In my experience, many techies don’t realize that there may be some differences in how each person in a group may define or understand technical jargon. My point, really, is just that in a group that gets this and is willing to pay the cost, the precision can speed up discussions that may be riddled with non-obvious ambiguity that may be more painful to clear up with simpler language.