Based on the article it also seems clear that a majority of the students who submitted scores (60% of admitted students) probably did so during ED:
The Office of Admission hopes to enroll a total of 750–770 students into the class of 2026, including the 473 who had already committed before RD. This means that there are 277–297 open spaces for RD admitted students for the University to meet their goal. The University also aims to bring 25 to 35 transfer students to campus in the fall.
To the extent that this may be true, it probably reflects the fact that fewer applicants are submitting scores in the RD round and those who do are being fought over by more colleges and universities than in years past. We know, for example, that some of Wesleyan’s biggest competitors are medium-sized research universities most of whom still require scores.
I would retract the “most of whom still require scores” part of that statement. Important competitors like Yale, Brown and Tufts have adopted multi-year experiments with TO admissions.
However, that doesn’t mean that there isn’t significant competition for applicants who do choose to submit scores. For example, if only 61% of Yale applicants submitted scores this year (which seems likely given last year’s reported results) that still translates as 30,000 applicants with submitted scores by the time their folders were being considered for admission. That’s twice the total number of students who applied ED and RD to Wesleyan this year - with or without scores. And, that’s just Yale.