Completely true. You have to understand the economics behind this to see why their claim is hyperbole at best and flat out misleading at worst. The fundamentals of scalable vector search is that you are dealing with potentially huge dimensionality and huge datasets, that means that memory consumption will be huge even for a modest (by today's standards) datasets. This problem has garnered lots of research attention, so making such a bold claim makes you think what Pinecone has under the hood that others don't.
Pinecone is VC backed and they have taken in to the tune of $50M in funding. They have to claim the "first" in solving these challenging technical problem, otherwise they'd have to really explain that their "secret source" is not really ground-breaking but relying on a series of open-source components under the hood. VCs wouldn't want to be backing yet another donkey in the derby. The truth is that solutions like FAISS, ScaNN, Weaviate, Quadrant, ANNOY and co. are working on this problem on a much more fundamental level. Pinecone and Google vertex matching AI are working on it on a application level. If Pinecones's solution is truly groundbreaking, they'd publish it in a more scientifically rigorous way. So these claims are to be taken with a grain of salt for what they are: developer evangelism/marketing speak.