No, you cannot choose a versatile heritage for Elf Atavism

Elf Atavism provides very specific rules in a system where specific overrides general.

• Generally, you choose a racial heritage
• More specifically, you can alternatively choose a versatile heritage
  • Understandably, rules are only given for character creation
• Even more specifically, you can take a Feat that gives you "benefits of the elf heritage" of your choice

A couple things of note - firstly, the feat specifies "elf heritage" and secondly, you "gain the benefit of" which is not the same as getting a Heritage.

No, you cannot choose a versatile heritage for Elf Atavism

Elf Atavism provides very specific rules in a system where specific overrides general.

• Generally, you choose a racial heritage
• More specifically, you can alternatively choose a versatile heritage
  • Understandably, rules are only given for character creation
• Even more specifically, you can take a Feat that gives you "benefits of the elf heritage" of your choice

A couple things of note -

1. The feat specifies "elf heritage" which is a specific subsection of heritages, not just any heritage an elf would have access to, and
2. You "gain the benefit of" which is not the same as getting a heritage; because you are not following the normal rules, you are not following the specific allowance for choosing a versatile heritage.

Then, instead of choosing a heritage from those normally available to that ancestry, apply your chosen versatile heritage.

Essentially, versatile heritage is available to elves, but that does not make it an elf heritage.