Bright way to inform about new extensions

I just saw that offer for Premium domain names sold "in a package" and I find that this is a bright way to offer them. If I am not so much in buying Premium domain names or participating to auctions, I believe that considering categories of TLDs is very important prior to buying a domain name at the regular price. For example, one would be interested to know that there is a dozen of domain name extensions dedicated to the business of Music. When preparing to buy a domain name to publish a content about Music...one should better know about what exists on the market.

Categories of TLDs did not exist in the past
In "the past", you would have bought a ".com", or a domain name from your country of residence ending in two letters. Today is different, when buying a new domain name within a certain business, it remains difficult to be informed that many extensions could match with the second level domain desired; even worse when the plural version of a domain name extension exists: if you are in the Real Estate business for example, you should check this list of domain name extensions before buying. I would also suggest to check that list of similar extensions too...and maybe that one too* for plurals.

What I saw
I follow a limited number of Twitter accounts and the Registry of African Geo TLDs Twitted this link on which you can read ".Africa - .CapeTown - .Durban and .Joburg domains from only $1.50 per slice". As a person interested in buying domain names from this region, I would certainly be interested in knowing that these domain name extensions also exist for the domain name that I am about to buy.

What about Registrars?
I know how difficult it is to create the right algorithm to suggest registrants the right domain name but unless I am wrong, and after checking at many registrars, all focus on the second level domain and none on the first level domain itself.

* These lists are frequently copied by Corporate Registrars lacking ideas ;-)