This just recently happened to me. Our company went bankrupt, and then we were offered new positions by the company that bought the old companies assets. Despite the break in service, we still weren't given an option on what to do with our 401k. In order to be "helpful" the new company just rolled at all over for us to their service provider. How convenient! No need to make any decisions whatsoever about what is going to be done with MY money.
If you're being given a choice, get it out ASAP. Roll it over to your own IRA be Betterment, Vanguard, or any of the other low fee brokerages (I use Fidelity and Schwab myself).