I don't think it will matter as HOA's enforce their rules accordingly. It doesn't matter the affluence of the neighborhood. Typically HOA"s exist to enforce rules set by the board to uphold the look and values of the neighborhood. I don't think they'll stop sending notices and enforcing rules just because the neighborhood is more affluent. It actually may be a stronger enforcement as the neighbors of the rule breaker will likely turn you in because they moved in to an affluent neighborhood because it was so nice (and affordable) and they want to keep it that way.
All my best
The first condo I lived in was a large, converted apartment building. Lots of wealthy people, generally middle-aged. I was 22 years old and just out of college. And the long-time residents were very, very picky. Later, I lived in a number of other places with more of the residents closer to my age and my socio-economic level, and it tended to be a lot more relaxed. The rules were still enforced, but it wasn't like the secret police were watching all the time.
In the years since, those early experiences seem to be fairly consistent.
If you're uncertain about a particular community, do this: Knock on some doors. Ask some of the residents. Seriously.
Hope that helps.
HOA's have a fiduciary responsibility to enforce the covenants, conditions and restrictions as written however in practice I see deviation. Some neighborhoods tend to be really strict and others are not so much. What might that mean? To me it seems precedent is fairly common, if you drive around and others are acting and doing as you want its probably a good thing. If in driving around you see things you really don't like, maybe its time to look elsewhere? Can they change, absolutely, the HOA could elect new individuals to the board and decide to enforce age old restrictions that have been let go.
The good news is that we have choices!! HA
I'm not a lawyer, this is not legal advice, just some practical advice based upon years of experience helping people purchase homes in the Phoenix metro area.