Irrelevant. A term can be well-defined and used correctly while also being diluted. In this case, I am pointing out that it's diluted by narrowing the category in which the claim is being made. I have no doubt that in this narrowed category, the term is being used correctly. This has no bearing on the fact that by narrowing the category in that way, this claim is made remarkably less impressive or interesting to many people hearing it, including myself
Terms can have multiple definitions and language is descriptive not prescriptive. If you intend to communicate that you mean "Pareto frontier" in the current context you need to include the word "pareto." If you don't then "frontier" will be understood as referring to mythos/astra/opus 5.5 tier models in intelligence (max capability regardless of tradeoffs). It doesn't matter that the second definition in the dictionary is the one you want to convey (charitably assuming you're not trying to mislead given the value of the hype of being able to call your model a frontier model) if your audience understands what you're saying to mean the first definiton.