Anyway, OP's argument doesn't resonate with me. The app store isn't a common carrier. Google doesn't need "valid legal reasons" to reject an app other than what is stated in their own terms. And just because Meta says it's okay to use "for Instagram" doesn't mean that Google is compelled to accept that reasoning. Thousands of different trademarked companies use Google Play. Does OP think Google going to have a different individualized policy for each company?
Here's what Google responded to OP, in part:
> The app also infringes Instagram’s rights in the registered INSTAGRAM mark by using “for Instagram” in the app branding without any other branding that is distinctive to the app. Such use is likely to create confusion by implying an association or other relationship with, or authorization by, Instagram when no such relationship or authorization exists.
The name of the app is
InPlan - Planner for Instagram
To me, that very much sounds like it's an app named InPlan put out by Instagram itself, and could be confusing. I agree with Google rejecting this title. Maybe if it was "InPlan - Unofficial Planner for Instagram" or "InPlan Planner (for use with Instagram)"
Plus, I question OP's interpretation of Instagram's policy. They quote Instagram's policy as stating:
> If you offer an app, website or a product or service that uses the Instagram APIs or is otherwise compatible with or related to Instagram, you may only use Instagram to say that your app is "for Instagram" or that the name of your campaign is "on Instagram" in a descriptive manner.
"In a descriptive manner" to me implies that "for Instagram" may be used in the description of the app, not the title of the app. I'm no lawyer, if the trademark attorney says it's okay, then it probably is, from a trademark perspective. But maybe not from the perspective of Google wanting the Play Store to clearly differentiate first-class brands from third party applications.
As far as I can see he didn’t retain a lawyer. He just had a consultation at best. That’s essentially meaningless. If you’ve ever worked with lawyers before, a consultation just gives you an overview of how the law works in the area you need help.
Unless you actually hire a lawyer, they aren’t going to look at the details of the case, and are just going to offer opinions on what you tell them.
Nothing was “confirmed by a lawyer” in any meaningful way.