It would be much better if they simply dedicated this database to the public domain.
In the "clarification" they indeed seem to consider that the database is covered by their copyright, and any free use is subject to their continued benevolence:
> However, ISO and its members do not charge for the use made of the codes contained in these standards, subject to this being consistent with ISO's copyright.
We're way off in speculation land here, but if CH law is like DE law, IIRC it's one of the countries that releasing to the public domain isn't really possible (which is why CC0 exists)
In the "clarification" they indeed seem to consider that the database is covered by their copyright, and any free use is subject to their continued benevolence:
> However, ISO and its members do not charge for the use made of the codes contained in these standards, subject to this being consistent with ISO's copyright.