You're right that international students in Canada are eligible for the CERB and that they will not be eligible, as of now, based on the design, for the Canada emergency student benefit. I have to say that there are other differences between the two benefits. For example, Canadians abroad will not be eligible for the CERB, but Canadian students studying abroad will be eligible for the Canada emergency student benefit. There is that kind of misalignment between the two. Again, the intent here was to cover all Canadian students, including those abroad, but the decision that was taken was to not cover international students studying in Canada. If other countries did the same as us, then obviously they would be covered indirectly.
As you mentioned, the government has allowed them to work more than 20 hours in the essential services sector, which is a plus for them for sure, but you're right about the fact that they are not, at this point, eligible for the benefit.