Do we actually know that more students than usual are being called off the W/L? It does seem that way given when they started (before end of March) but that might be for other reasons as well, especially if they under-admitted in the regular round and are using the w/l round to put on finishing touches.
Not sure that opting for a gap year is a one-way decision; the school can always say “no.” Also, not sure that you can make a decision to gap after committing to enroll, as that young lady in the second article seems to suggest she’s planning to do. You can probably “defer,” but doing so might toss you back into the applicant pool 
Also, anyone offered merit at their college will need to find out what the rules are if they gap. Some schools might re-evaluate the eligibility.