No, that's not right.
The services offered by plastic molding companies are a critical element of the industry.
As well as pumping out critical components for manufacturers of finishes medical devices, many of these subcontractors also offer design, assembly, packaging and (out-outsourced) sterilization.
They will need to incorporate recall procedures, risk management etc etc.
To all intents and purposes they
are medical device companies, just with less clinical interface.
And a very large proportion of these companies hold ISO13485 (just open any trade magazine). A finished medical device manufacturer will actively seek out such suppliers.
Now I'll admit I'm biased (it's the product I sell after all!

), but I would hold that both the suppliers* and the finished device manufacturers are generally extremely happy with the whole system. It provides visibility, security, and improvement over time.
*not just plastic molders, see my above post