Where has the Middle Gone?

The following is based on my own observations and does not represent the opinions and experiences of the CI/ADI community as a whole. I am only speaking for myself here.

One of the tenets which I leaned when adopting a CI/ADI-based classroom was "teach to the middle" - teach to those students who are between the high-flying, achieving 4%ers and those not doing well in our classes. I like how Judith Dubois puts it in her blog: 

[The middle] are students who have difficulties but are willing and make an effort as long as they can understand. When the teacher sees that they are not understanding, [the teacher] backtracks so that the entire class can follow.

Many times we refer to these students as our barometer students, those students to whom we look to tell us how well the class is understanding something and when we can move forward. These are our target students when teaching.

However, since the return to a post-COVID/hybrid classroom, I am struggling with teaching to the middle. Upon the return to full in-person last year, I anticipated that there would be major knowledge gaps in my Latin classes, especially in my Latin 2 classes, since most had been digital students for Latin 1. And indeed, there were as I had anticipated. Therefore, I knew to manage my expectations. I moved at a slower pace to fill in knowledge gaps while moving forward with new material. I moved the goalposts from previous years of what I normally would be able to cover to an adapted curriculum which truly focused on sheltering vocabulary and not grammar - almost to a overly nauseating degree!

Flash forward to this year, and something with which many others and I are being confronted head on in our current levels 1 and 2: there is no more middle. Before COVID, while classes still had high flyers and struggling students, it seemed that there was a distinct middle to whom to teach and to target. Now post-hybrid, there is a WIDE chasm between the high-flyers and those struggling, with very few students who can serve as barometer students. I feel like I have students falling into two categoies: those who are doing very well in my class and those who are failing very well. I have never seen it before to this extreme. 

So I have to ask myself the following questions:

1. Just how much are we still dealing with knowledge and behavioral gaps from hybrid/digital teaching? These level 1 and 2 students never took language digitally/hybrid but were here for level 1 in full in-person classrooms, i.e., there were no L2 knowledge gaps per se to fill due to hybrid/digital. Many of these students were in middle school during hybrid/digital teaching.
2. Are there literacy issues involved? Am I dealing with something which is bigger than I can address on own and needs to be addressed by special education? 
3. Have we conditioned/trained students to think that they are not responsible per se for their learning? I will admit that during hybrid and last year to a degree as a teacher I was accepting missing work MONTHS LATE and lowered my expectations of what a passing student was. But the reality is that it is no longer 2021-2022 - is it wrong for me to expect a pre-Covid academic setting since things appear to be back to normal (or as normal as they are going to get)?
4. Do I need to adjust my view of what doing my 50% and what students' 50% mean?

These are questions which I am asking myself so that I can determine where I need to manage my expectations. What observations have you noticed about the middle?