I prefere the developer time to be used to create good sounding, bug free and well working optimised applications with features for old, new and future music. The audio and the musical functionality is imho the most important.
If that's done, and if the cloud feature don't use ressources like RAM, CPU power and many developer ressources, - don't create any audio issues and can be switched off, then perhaps a Arturia cloud feature can be okay. But why, when there are other options to back-up presets?
I agree Arturia can improve things like the import and export preset function. But it's for example also allready possible to backup imported and own created presets, and then copy them to other computers very fast and easy without using export/ import of banks or presets. On windows copy the presets in the hidden folder ProgramData.
And it's also allready possible in other ways to use other personal cloud services and/ or disk back-up system like using the systems you mention to back up files. Is'nt it? What can a Arturia Cloud system add to this?