As you were! (Basically)

The Valenician Decree has been challenged and its been pointed out that motorhomes are vehicles in their own right so are not to be governed by the tourist authority but by 'traffic regulations'.

Meaning that if parked legally its all good wherever that is

Extract from the Spanish info from ASEICAR, the employers' association of the caravaning sector in Spain

'We understand that the definition of motorhome itself, being a vehicle, cannot under any circumstances fall within this prohibition (as it is governed by traffic regulations) and in this sense, our association has urgently addressed the different people responsible for Tourism of the Generalitat Valenciana in order to clarify this discrepancy that could seriously harm the sector.'

'Once the meeting between ASEICAR and the regional body has concluded, the General Directorate of Tourism of the Generalitat Valenciana has issued the following statement : « In relation to the doubts that are being raised regarding what is stated in article 2, section 5 of Decree 10 / 2021, of January 22 , of the Consell, by which the Regulatory Regulation of tourist accommodation of the Valencian Community is approved , it is reported that paragraph 5 of article 2 of the aforementioned Decree excludes from the application of this parking with or without overnight intention of motorhomes, since it does not prohibit or regulate theparking of these vehicles since this issue is not the responsibility of the tourist administration.'

Full article here (in Spanish) https://aseicar.org/la-comunitat-valenciana-puntualiza-prohibicion-de-la-pernocta-de-autocaravanas

Glad someone has followed this up or it could have spread to other regions.
Both sides here have valid arguments in wishing to organise the way that legally used vehicles can park.
I wait for the outcome on this and hope the Spanish Police do the same.