Are you talking about acceptance rate in terms of successful applicants who matriculate into the university in the fall, or acceptance rate in terms of offers made? As the two are very different things.
Maths at Warwick, it's flagship course which is considered among the top 4 in the UK and considered to be extremely competitive, had before covid an offer rate of around 90%. However, every offer had a STEP condition which most failed to achieve.
Since MORSE is offered in conjunction with the maths department I suspect it may have a high offer rate but also STEP conditions attached to that.