Case Western has a different admission model than the colleges that are most frequently discussed on this forum. Many Case Western applicants are accepted EA – not just those who switch to ED2. Some sources report a much higher EA acceptance rate than RD (I suspect they are copying EA admit rate from USNWR, which reports both EA and ED rates in their pay site). Decision threads on this forum also suggest a high acceptance rate for EA. For example, it looks like the majority of posters in the 2023 EA decision thread at Case Western Reserve Class of 2023 EA Results Thread - #3 by Proudmom2023 were accepted, including both some top stat kids and some decent stat kids. A good portion were also deferred. Hardly anyone was rejected in the EA round. In the thread, some suspected that many of the high stat deferrals relate to Case Western being need aware, rather than yield protection.
Perhaps more relevant to “yield protection” is Case Western’s waitlist policies. Some example waitlist numbers from Case Western’s CDS are below. In the sample years, Case Western consistently waitlisted ~10k kids, which is more than 1/3 of applicants – far larger than colleges than occurs at other colleges that are frequently discussed on this forum. The number waitlisted had less variation than number accepted Case Western seems to admit however many kids they need to from their huge waitlist to meet their target enrollment of ~1350 kids. They might admit 0 kids from the waitlist if the have a higher than expected yield or they might admit as large as 1076 from the waitlist, as occurred in 2020 with kids choosing not to attend due to COVID.
This does appear to be a form of “yield protection” for the college. Case Western has a very low <15% yield on EA+RD admits, which I imagine makes it awkward to predict enrollment totals well. If EA+RD yield in a particular admission cycle is lower than predicted, they use their waitlist to make up the difference and meet target enrollment. If EA+RD yield is higher than expected, they admit few/none from waitlist to minimize degree of over-enrollment.
2018-19 – 10k waitlisted (37% of applicants), 8k accepted (29% of applicants), 0 admitted from waitlist, 1393 enrolled, Yield = 18%
2019-20 – 10k waitlisted (36% of applicants), 8k accepted (30% of applicants), 209 admitted from waitlist (2.5% of admits), 1357 enrolled, Yield = 17%
2020-21 – 10k waitlisted (34% of applicants), 9k accepted (30% of applicants), 1076 admitted from waitlist (12% of admits), 1304 enrolled, Yield = 15%
From a student’s prospective, I don’t think there is an obvious yield protection downside from applying EA instead of RD. Most kids who post on this website (typically high stat + high income) seem to be admitted EA, and the rest are primarily deferred. Case Western seems up front that they give a boost for ED, which is understandable given their low yield and consideration of demonstrated interest/need. However, this does not mean that RD has better admission odds than EA (without switch to ED2). I see no reason to expect that the kids who are deferred → waitlist in EA, would have a better non-waitlist result had they applied RD.