I think you have identified some small truth, but have made an error in narrowing the scope of where the deficiency actually lies to the individual/group. Exceptions can imply deficiency (among other things) but I would argue that said deficiencies often are in how these groups are treated by society and not inherent to the groups or individuals themselves.

I’m going to use calculus as an example, since there are plenty of reasons you’d expect someone to not be able to do calculus. If you’re sufficiently young, maybe you don’t have the complex reasoning skills to understand calculus (deficiency, but not permanent). If you’re an adult without a math education, would your inability to do calculus be considered a deficiency, or just a lack of opportunity which can be fixed through assistance? If you have been told your kind of person would suck at doing calculus but you really want to learn, and are performing worse than your peers who are told they are good at this naturally, is that a deficiency in the individual or the system they live in? If you have to work more than one job to keep your family housed and don’t have time for calculus, if you are targeted for police violence, if you’re discriminated against by even the most well-meaning people with authority over you, you could be the most brilliant mathematician and it wouldn’t matter- society at large is failing you.

When you’re talking about “exception” here, I think what is really happening is people taking measures to level the playing field for people who have experienced discrimination. In a perfect world with no individual or systemic discrimination, current or historical, these sorts of “exceptions” wouldn’t be necessary! But that’s not the world we live in. The first step to making a more equitable society is recognizing where people got shafted historically and what affect that still has on society today. Getting the short end of the historical stick does not imply immutable qualities about a group of people today.

So, no, I don’t think that giving exceptions to people who need them most inherently implies that they are individually or categorically deficit.