In my experience, international students say nothing in class and write huge bibles of notes. It's nothing to do with their effort. But I do agree that replacing critical thinking modes of evaluation, such as essays, with simpler means such as multiple choice is lowering the standards. It is certainly not as effective a learning and assessment tool.
The best way to deal with it is to provide English assistance and support services but keep the standard as it is. That way the opportunity is there for people who struggle with English to seek help, while the legitimacy of the course quality is upheld. Thankfully USyd tended to do this in the Eco + Business faculty when I was there. I remember my lecturer saying - "Look English is important, you need it in this course and you are expected to be able to use it proficiently. That said, if you need assistance please do not hesitate to go to the learning centre and get help."
Lowering the standards for international students because of language barriers is just not on, in my opinion. Given the necessary support, it can be avoided.