Kinda interesting that this is getting so much attention.
Ultimately, the example.com domain is just there so you can use it in documentation or code examples. Your expectation about the actual example.com domain should basically be none at all, maybe with the exception that it's hopefully not doing actively malicious things like serving malware or running a catchall mailbox feeding spammers.
Whatever HTML they server or if they serve anything at all... shouldn't matter.
Ultimately, the example.com domain is just there so you can use it in documentation or code examples. Your expectation about the actual example.com domain should basically be none at all, maybe with the exception that it's hopefully not doing actively malicious things like serving malware or running a catchall mailbox feeding spammers.
Whatever HTML they server or if they serve anything at all... shouldn't matter.