Are you sure he didn't mean being converted into a catholic?
Yes, I am sure, and for a number of reasons. Rome has for years absorbed native peoples without requiring them to give up their pagan customs (although it wasn't always like that). Instead, they are integrated into the local church. One has only to look at Central and South America to see it.
The Council of Trent placed all Protestants under anathema. That has never been recinded.
Dr. James Dobson visited Mother Theresa in India. While he was there he asked her how she went about witnessing to the local people. She replied that there was no witnessing because there "are many paths to God". The late Pope held the same view. In short, what she did (and Rome in general does) is minister to the body without ministering to the soul. Ecumenism and church growth have replaced evangelism.
What is happening in Rome is very similar to what happened in Ephesus:
the Revelation 2:1-7 "Unto the angel of the church of Ephesus write; These things saith he that holdeth the seven stars in his right hand, who walketh in the midst of the seven golden candlesticks; I know thy works, and thy labour, and thy patience, and how thou canst not bear them which are evil: and thou hast tried them which say they are apostles, and are not, and hast found them liars: And hast borne, and hast patience, and for my name's sake hast laboured, and hast not fainted. Nevertheless I have somewhat against thee, because thou hast left thy first love. Remember therefore from whence thou art fallen, and repent, and do the first works; or else I will come unto thee quickly, and will remove thy candlestick out of his place, except thou repent. But this thou hast, that thou hatest the deeds of the Nicolaitans, which I also hate. He that hath an ear, let him hear what the Spirit saith unto the churches; To him that overcometh will I give to eat of the tree of life, which is in the midst of the paradise of God."