Google vs Oracle is about reimplementation of an API. So if someone came along and created a software that provided a Blender-like API, then that shouldn't be violating copyright.
Usually GPL software that provide an API that would allow proprietary software to be built on it tend to have an exception for the API. From what I understand, Blender doesn't provide that.
Google vs Oracle is about whether an API can be copyrighted. If the API can be copyrighted, then Google can not write their own implementation. If the API can be copyrighted then Google can not.
The internet predicts disaster if Oracle wins. Because if an API can be copyrighted then all the software that uses an API suddenly becomes illegitimate. All kinds of terrible things can happen. Then web is built on APIs!
Blender has a plugin API. Plugin software uses that API. Blender is written with GPL and the GPL author believes that even DYNAMICALLY linking an API constitutes a derived work (copyright term) and therefore the dynamically linked software must also be released under the GPL.
However if Google defeats Oracle and it is determined that APIs are not subject to copyright protection then I don't see how dynamically linked plugins that are merely use an API can be blocked by copyright.
There may be a universe in which using an API is copyright protected but rewriting the code behind an API is not. That would be highly unusual imo. And I do not think that would be the narrow fallout of Google winning versus Oracle.
Usually GPL software that provide an API that would allow proprietary software to be built on it tend to have an exception for the API. From what I understand, Blender doesn't provide that.