All Northeastern CS students are automatically enrolled in their first two semesters of CS courses, so there are zero issues staying in sequence. After that there is flexibility but generally the “sequenced” path is still followed and classes are available. The sections are typically made to match enrollment, so by that metric, it will look always full, but the availability is flexible.
The only people that would have any sort of issue getting into Northeastern’s intro CS would be non-majors or minors.
I’d fully recommend Northeastern here for many of the reasons listed in post #7