Do T20 admissions officers filter people off by GPA preliminarily?

Answered

Yes and no. If you go to a Top 10-20 boarding/prep school which is in a way their own Ivy league, then you get some leeway because inevitably the course rigor will be hard and there will be lots of opportunities to do sports, ECs, and develop a spike. But if you go to an average school where the school average SATs are like 1080 and you are struggling to keep up a 3.5, then no.

One failure educators, colleges, guidance counselors, parents, students, and consultants made was the suggestion that everyone applies to many reach schools because of the test-optional loophole. No one anticipated that T20 research universities and Top Liberal arts colleges would get 20-60% more applications. It's like everyone rushed to get a PS5 that the demand was so high the prices skyrocketed. During this college cycle, everyone crowded into the Top 40 college space when there were even fewer places to fill than last year because of all the deferred admissions. So no one expected the early decisions and early action cycle to be so brutal. Most people were rather optimistic instead. Since Sunday, RD admissions have been trickling out. So far all I read was that MIT had 1340 total admits (4% based on 33240 applications) with 719 SCREA admits (4.8% based on 15036 applications) and 621 RD admits (3.4% based on 18204 applications). This compares with 7.3% last year so that means getting in was 46% percent harder this year even though everyone was test-optional. If that is any indication of how the Ivy day is going to look in 3 weeks, it's going to be ugly. We may see RD admit-rates in the 2-4% for some Ivys. Fasten your seatbelts.

My advice to you is to over-deliver and whatever you think your preparation needs to be - double it if you are applying to T20 schools. Why? Because I seriously feel that 99% of the colleges are going to be test-optional next year and there will be more students applying with incomplete transcripts because they will have at least 3 full semesters of non-grades or Pass/Fail grades or something similar. This will make it even more complicated for admissions officers because they will have to use some kind of predictive modeling to guess what the "true and real" GPAs should be if High Schools were not compromised. The last 5 years of admissions data were very useful to everyone until this year. Now we there is a paradigm shift and you can't use old admissions data to benchmark what the new admit values and criteria are going to be. After April once everyone reports admissions rates, this will be a great time to collect all this data, crunch it and come up with new levels for next year and the following cycle.

What I predict is that top publics like UVA, UMich, UCLA, UC Berkeley are going to have record low admit rates. Also all Ivy Leagues, Elites, and Caltech/MIT. I think near Ivys like RICE, Vanderbilt, Northwestern, Notre-Dame are going to be slightly lower and then your NYUs, Tulane's, UMiami, Northeastern, BU, BC are going to be around the same. I do think your top liberal arts colleges are going to be lower admit rates but the next 2 tiers might actually have higher rates because no one was focused on them this cycle. So I'm thinking your Wake Forest, Trinity, Washington Lee, Davidson, Bryn Mawr, Pitzer, Carleton, Lehighs, Union, Macalesters might be the way to go since they may have lost a lot of international students and full-paying students this cycle. I might be wrong but everything will be known in 3 weeks.

As a practical matter since you have 2 full summers to work on this, try to swap out those bad grades by taking them over in the summer either through dual enrollment, online HS or college courses, or MOOCs like eDx. If you are diligent about fixing what's broken that's more important than loading up on ECs you're not passionate about. 40-50% of the main criteria for T20 schools are academics so if you can't pass muster there, they won't consider you.

Hope this was helpful.