It looks like "immigrated to" is now more popular in American English (https://books.google.com/ngrams/graph?content=immigrated+to%...), but not in British English (https://books.google.com/ngrams/graph?content=immigrated+to%...).

No idea where you got those definitions.

An immigrant is one who arrives and moves into a place or country.

https://en.wiktionary.org/wiki/immigrate

An emigrant is one who leaves and moves out of a place.

https://en.wiktionary.org/wiki/emigrate

This distinction is very clear and has really never been a problem for people who understand language. The English Wikipedia has somehow managed to fuck it up beyond all recognition, so congratulations! You're one of Today's Lucky 10,000!

I prefer 'migrated' for exactly that reason - strips all the annoying modifying prefixes that can trip you up. More flexible word, less radicals! ;)

It's funny to me people are only discovering this about America now whereas a whole generation of 1st gen parents of current Americans discovered it in earlier waves, the tech waves, etc.

Both "immigrated to" and "emigrated to" are correct, and mean the same thing; they just emphasize, slightly, different things.