Oh, the Catholic Church had way more than 7 local parishes when John wrote Revelation.
What you didn’t find back then was a Baptist Church, Presbyterian, Methodist, Mormon, seventh day adventist, etc.
That confusion was over 1,400 years away.
There was no Catholic Church, and no catholicity of churches. There were local churches planted all across the known world at Paul's time, each of which was independent, autonomous, baptizing by immersion, goverened by elders, and doing what Baptists and Brethren do today. Catholicity was a concept later introduced by marrying the Platonic concept of oversoul with extrabiblical church polity by Gentile philosophers who grasped the reins of power by unifying with the Roman government as its religion, and overcoming Scriptural Christianity.
Good way to AVOID discussing the ERROR in those 7 CATHOLIC churches!
Apparently Rome wasn't one of them.