I’ll keep it short.
- mom has decent amount 401k in Oppenheimer
- her company is changing from Oppenheimer to http://www.geneseevalleytrust.com/
- she doesn’t want to change but is being forced toIs this BS or is it just me?
Its my understanding that you can leave your money where it is… In my situation, I have a decent sum of funds with fidelity - - when i took a new job i had 4 options
roll it into my new 403b
roll it into an ira
leave it alone
withdraw.
I choose to leave it where it is cus i <3 their international funds. I now have a 401k with Fidelity and a 403b with my new company… works good because if the avg rate of return stays where it is the Fidelity will grow nicely 
… also if i ever go back to a company that has Fidelity, i can start contributing back to that fund.
there is no reason to keep all of your money in one bucket…i say she can leave it. but it looks like she has no option but to start contributing to the new fund.
then again, i would have her call up the old and new investment co and ask them whats best for her situation… in my case… i have a long time until i retire and t might make sense for your mom to roll it into the new fund…