TL;DR - They want to allow riskier and more expensive investments into 401(k) accounts.
Many 401(k) options can be pretty crappy as it is now, and as boring as it can be, we need to ensure we understand what we're signing up for if we don't expect to be screwed, just as in any other financial situation. Learn the basics of investment saving, set up your own brokerage account, and do a regular sweep of your funds into your personal low fee account as frequently as your employer plan lets you.
Yes, it sucks that they are attempting to remove guardrails, but this shouldn't be anything new for anyone with a retirement account. If you don't understand what you are investing in, you've already likely failed yourself. Everyone should at minimum be able to understand the terms of your 401(k) policy, know what different asset classes are, and know what expense ratios are. Getting informed keeps us safe. Trusting an employer or financial product salesman is not the way to go.
For anyone wanting to start on basics, from simple to more involved: