To date all who desire the CS major can do it if they meet prerequisites.The elite students will likely take some classes for honors and more math.
btw- it is a misconception that CS is a harder major than some others. The difficulty of a major is determined by aptitude and background. For some math is easy but writing difficult. I would consider a math major more difficult than a CS one because of the abstract thought processing needed. btw- some CS and math courses are cross listed (ie same class but course listing in both depts).
A great thing about UW is that an entering student is not confined to the proposed major they enter with- or even school/college. Some majors have space limitations that make them competitive. Perhaps in the future CS will have limitations due to its vastly increased popularity in recent years. Supply and demand economics- not difficulty.
Students with less ability will likely find upper level courses too difficult to succeed in and will not graduate with any given major. Some with a poorer HS background may need to work harder, take more courses to succeed in any given major.
Let’s not glorify CS. Just another average major for those with a math bent instead of other fields. Remember that CS majors will pursue jobs in varying diversity of work and levels of skills needed to do well.
disclosure- son honors math major who added the CS major and now in CS work.