You don’t need to provide root access just because you used GPL code, you just have to follow the GPL.
Well, to follow version 3 of the GPL, you do actually need to provide effective root access.
Specifically, version 3 of the GPL adds language to prevent Tivoization.
It’s not enough to just provide the user with the code. The user is entitled to the freedom to modify that code and to use their modifications.
In other words, in addition to providing access to the source code, you must actually provide a mechanism to allow the user to change the code on the device.
The name “Tivoization” comes from the practice of the company TiVo, which sold set-top boxes based on GPL code, but employed DRM to prevent the user from applying custom patches. V3 of the GPL remedies this bug.
I think they’re just stopping operations of the company in Brazil.
But I don’t think they’re going out of the way to prevent Brazilian IPs from connecting.