This seems like a stretch. The site doesn't, as far as I'm aware, have any control over who links to them in any form, including Facebook shares. I think it's unjustified, not to mention totally impractical, to say that a site can never change content it's offering (for free, no less) after it's first been published, just in case someone already linked to it and didn't like the change.
It's also not at all unreasonable, again IMHO, for a site that didn't start with ads but suddenly receives an abnormally high level of traffic to introduce ads at that time. Someone has to pay the hosting bills, after all.
A better bet if this mechanism is being abused might be to establish some sort of standard whereby a link could include a checksum that would then be invalidated if the linked content subsequently changed. This way, anyone following the link (including any hosting sites that share that link) could confirm whether or not what they were seeing was what was originally linked. You could take this further with some sort of standardised changelog and last updated indicator that sites could make available if they wanted to, and having browsers that detected a mismatch in a checksummed link warn a user before displaying the page and include recent update information if the site provided it. Lots of details would need working out, though, and I'm not sure I see enough upside to justify the complexity and inconvenience.
It's also not at all unreasonable, again IMHO, for a site that didn't start with ads but suddenly receives an abnormally high level of traffic to introduce ads at that time. Someone has to pay the hosting bills, after all.
A better bet if this mechanism is being abused might be to establish some sort of standard whereby a link could include a checksum that would then be invalidated if the linked content subsequently changed. This way, anyone following the link (including any hosting sites that share that link) could confirm whether or not what they were seeing was what was originally linked. You could take this further with some sort of standardised changelog and last updated indicator that sites could make available if they wanted to, and having browsers that detected a mismatch in a checksummed link warn a user before displaying the page and include recent update information if the site provided it. Lots of details would need working out, though, and I'm not sure I see enough upside to justify the complexity and inconvenience.