AdultBlock scam? Is there a downside to doing this instead....?

[av-seo]

So our IT guy just sent me an email from our domain registrar, encouraging us to sign up for an annual 'adultblock' service. For those that aren't sure what this is...

Adultblock represents a straightforward mechanism that enables qualifying organizations to block the registration of any domain that falls under their trademark. This includes unlimited variants based on the holder's labels.

Instead of worrying about registering and managing many different adult related TLDs, it is possible to block trademarked domains under all four TLDs for up to ten years through just one action.

Unfortunately, this service is not cheap, and I'm starting to wonder about the 'downside' of NOT doing it. Does anyone know if just purchasing the adult related TLDs for our domain, and then just sitting on them, would have any sort of negative effect on our SEO?  Alternatively, could we just set an alert for when / if those domains ever get purchased and then just disavow those sites in search console?

Thanks!!