com, net, org, edu, gov, mil, arpa were the original 6 introduced in RFC 920 in 1985.
In the early days .com was not as dominant as it became in the late 1990s up to now. For example, up to Apr 1, 1987 there were 94 .edu registered but only 66 .com.
Of course many of the country codes are almost as old as the original 6.
Various alternative extensions predate the new gTLDs by about a decade - e.g. .coop was introduced in 2001 and .pro in 2004.
I think the creators of the above examples didn't hear about anything but com/net/org (and maybe .ru lol). Saturday Night Live's video is from 1999 when .com was already dominant. Creative people were thinking beyond the comnetorg all the time.