Hi Niels,
Can I ask why believe these two locations are not caravan sites please?

From the basis of *many* ground surveys, these sites contain no permanent customer buildings, such as tourism=chalet.

They instead house static caravans with wheels which are moved every few years as pitch rentals are updated.

I can see the utility of adding an extra tags like permanent_camping=yes 
static_caravans=yes, but not chalet as these are permanent features.

Can I invite you to engage with the UK community at https://lists.openstreetmap.org/listinfo/osmf-talk please? 
There are *many* UK sites with the same tourism=caravan_site tagging (operator=Havon, operator=Parkdean Resorts UK Limited, and many more) and discussion is always best before mass edits.

Happy Mapping,

James