If you are an L4 (basically starting at OAI), the median PPU package is $315k [0] and that's valued from the last tender offer round. So that means an exit of ~$945k.
[0]: https://www.levels.fyi/companies/openai/salaries/software-en...
[0]: https://www.levels.fyi/companies/openai/salaries/software-en...
That being said, it's hard for me to believe many employees don't have 10x the amount you mentioned, and will be able to get ~1m worth for 10% of their shares.
I could be 100% wrong on both fronts - but it's my 2 cents