On the official sit where you have to choose a cpu to download the wallet there are many models missing.
In fact, all those earlier intel core i5/i7 like sandy bridge that support avx but not avx2
As a result, that wallet version is never recommended for download and users are force to choose standard instead
The standard version is for non-avx2 CPU's.
If you select any of the CPU's in the list, the AVX2 version is shown.
This is correct.
(Go and try running the AVX2 version on a non-AVX2 CPU, report back your findings)
The list as is can be a bit confusing
especially for those with a fringe processor, that are old, but not that old.
For instance I downloaded the AVX2 version for an early i3 and the program wouldn't work, it just crashed without an error...
The wallet needs some work done, it would be nice to have an indicator of when it's mining or not, and a warning when it detects a not supported processor.