This whole discussion is like arguing how many angels can dance on the head of a pin. It depends completely on how you define open source, and there is no single universally agreed upon definition. Per this article, there are over 80 variations of open source licenses all with different term and conditions. Some are more permissive, some less so. Yet they can all be considered a variation of open source, though I’m anticipating you wouldn’t agree? For this particular app, there are some restrictions in place aimed to protect users from malicious forks. IMO this is a good thing. I can’t understand why you are acting like the definition police here, it seems very pedantic tbh.
Many software buyers – even new developers – misunderstand the term “open source” to mean the software is available to use, copy, modify, and distribute as desired. This misunderstanding may arise from confusing open source with public domain or shareware, both of which are free to use and modify without specific permissions or licensing.
The truth is that, for the most part, open-source software is covered by one of several types of open source licenses and is not necessarily free of charge either.
In contrast to proprietary software where vendors typically make it impossible to access, copy or modify the source code, open source code permits the use, reuse, sharing, modification, and distribution of the code in other programs or applications. But just as with proprietary software licensing, open source software is subject to various legal terms and restrictions, depending on the type of open source license in force.