I think there was a similar situation in Crete 2/3 years ago, but not so much today.
In 2004/2005 a local (British)villa rental company owner was arrested here and charged with running a business without licences. As I remember there was a large outcry and panic among foreign owners – and few had heard of the Greek EOT licence. Looking around the web and estate agents sites there was no mention of licences to rent back then, and some of the first information about EOT licences was published here on the Living in Crete website www.livingincrete.net/EOT.html
Within a few months the whole issue had been widely publicised and suddenly all the estate agents were mentioning EOT on their websites, and owners were rushing to get licences.
It's interesting to see that, when googling for renting out Spanish property very few companies mention that you need a licence. Google for Greek property rental and EOT appears on nearly every agents page. One of the companies I checked have properties in Spain and Crete. On their Crete info page they mention the EOT licence, on the Spanish info page, no mention of any need for licences. It's what they have been getting away with for so long, and was similar in Crete before 2004. Portugal seems to be another country where tourism licences to rent have been ignored for a long time but the authorities are catching up now.
Thankfully it seems that in the last year or two estate agents and developers in Crete are more informed regarding EOT requirements and most now ask at the outset whether the buyer intends to rent as a holiday let , as a different building permission is required for tourist properties.
I’m sure there are still a few dodgy practices (by owners or builders) but it seems that the crackdown in Crete happened a few years ago and now most are aware of the requirements.
It would be interesting to hear comments from buyers / owners, or potential buyers, in Crete regarding their experiences of information given about buying to rent ..