What we have already become familiar with for the new gTLDs - the verification of each holder contact by confirming a corresponding mail request - was also introduced for the well-known generic domain extensions from the beginning of October 2014. Affected are
.COM, .NET, .ORG, .INFO, .JOBS, .BIZ, .NAME, .TRAVEL, .AERO, .MOBI, .TEL, .ASIA, .XXX, .PRO
No, you do not have to answer confirmation requests for every domain already registered with one of these endings. A one-time validation of the email address of an owner contact is sufficient for all domains where the owner contact is registered.
At the latest when you re-register such a domain, modify it or change the email address of the holder, you will receive an email request to the address specified for the holder. If you do not answer this, your domain will be deactivated.
So in your own interest, please watch out for such email enquiries and ask us if you are in doubt!
If the email address entered in the holder contact is no longer correct, the verification request can of course no longer be delivered. It is therefore best to take the precaution of checking whether all your holder data for domains under the 'old' gTLDs are correct!
Certainly, these measures will improve the quality of the contact data registered with the domains. However, due to the known procedures for Whois anonymisation, which is available through a large number of providers, it becomes questionable whether the set goal can really be achieved. And it is certainly not a contribution to "simplify your life".