"401k Admin (Fidelity) told them it is passed the dateline to withdrew 2020 excess contribution>"

They have missed the deadline for it to be moot. The deadline for the corrective distribution to treat the offset to the contribution as if it never happened, is what has passed. As long as they still work for that employer, they should file for a corrective distribution. But now, because they missed the deadline, you have to deal with excess contribution excise tax and tax on earnings. Roth 401(k) contributions are not pre-tax, so you would not need to add that back as taxable income, but I would confirm it is part of the W2 income:

https://ttlc.intuit.com/community/retirement/discussion/roth-401k-excess-contribution/00/1260741

This is similar to your HSA issue. Take it year by year.

Start here:

https://www.investopedia.com/what-to-do-if-you-contribute-too-much-to-your-roth-ira-4770686

https://www.investopedia.com/ask/answers/158.asp