I should admit reading your example, yes, not all preventative actions are necessarily contributing to continuous improvement, so I am okay with using "could" instead of "are" in that context.
Let me have an illuminating example.
There is "Company A" , subject to ISO9001, and as part of their continuous improvement program they decide to minimize the administrative burden on the activities carried out as part of the Document control.
As a result of it, they have identified and executed actions like:
1., have minimized the review rules for documents,
2., optimized the approval procedure,
3., electronic document management system is identified to be implemented,
4., etc. etc.
As result of it, they have managed to reduce the time spent on documentation administration with X%, documents are more accurate, customer satisfaction survey also shows some improvement, blablabla.
There is "Company B", subject to ISO13485 only, do not really plan to do anything particular for continuous improvement.
One of the internal audit identified deviations from the procedure defined in the QMS for document control and the practice carried out on a regular basis.
Investigation and root cause analysis were carried out and it was identified that (next to people were not well trained, etc.) there are far more burden on the document control process than it is needed based on regulatory needs and business needs and this is due to the fact that the document process was never evaluated whether or not suitable for the changed environment and it has survived like a dino from the medieval times of the company.
So ... the corrective action was about how to retrospectively carry out activities if needed and to maintain appropriate knowledge transfer about document control procedure, AND in order to kill the additional root causes they've identified further actions as part of the corrective actions:
1., have minimized the review rules for documents,
2., optimized the approval procedure,
3., electronic document management system is identified to be implemented,
4., etc. etc.
Now ... can we say, that even for Corrective Actions, we can not talk about continuous improvement?
Many thanks, Cheers!