The other shoe to drop is the actual play community. Critical Role is all but in-house already and probably won't be affected, but smaller creators trying to monetize their 5E content are going to start feeling the noose tighten.
> The original OGL granted “perpetual, worldwide, non-exclusive license” to the Open Game Content (commonly called the System Resource Document) and directed that licensees “may use any authorized version of this License to copy, modify and distribute any Open Game Content originally distributed under any version of this License.” But the updated OGL says that “this agreement is…an update to the previously available OGL 1.0(a), which is no longer an authorized license agreement.”
> The new document clarifies further in the “Warranties” section that “this agreement governs Your use of the Licensed Content and, unless otherwise stated in this agreement, any prior agreements between Us and You are no longer in force.”
The hinge of the trap in OGL 1.0a is the "any authorized version" part, here in its more full context:[1]
> 9. Updating the License: Wizards or its designated Agents may publish updated versions of this License. You may use any authorized version of this License to copy, modify and distribute any Open Game Content originally distributed under any version of this License.
Hasbro has the money to make legal challenges to that prohibitive, and no other company in the space has remotely similar resources. Good luck, suckers!