It's an important distinction that wasn't made, true.
My point was assimilation should be up to the individual, never the country, otherwise it doesn't work and can even turn into a tragedy (native Americans, Uyghurs', Copts, the middle east etc.).
Assimilation is a choice, not good or bad in and of itself and can't be judged. This is where the distinction come to play as I think integration is almost always good and correct.
The only responsibility of a country is to guarantee or allow both options and encourage the latter. You just can't force people to do either.