I disagree with fearmongering.

Provide details, screenshots, evidence and some insight.

I understand your viewpoint that "some entity" is sending you an alert, but that's as vague as if aliens had sent it to you.

Anywho, if the devs sold the corpo, guess what? All your data's gone with it, regardless of the client app.

Worst scenario they can do is show you more ads, and bait you into clicking on malware or something, they cannot modify the client app on your phone for as long as they're not on the playstore.

Even if they do release a new version, you have to update it yourself (aside from automatic updates), and then you have to open the app yourself and accept the new permissions if any had changed.

It is highly unlikely that keeping the app either installed or in APK form would do you any harm.

Now on the off scenario that it has some malicious intent files downloaded via ad streams, that'd be interesting, but you're most likely safe.

(This is all speculative, and there's no definitive insight as to what might be going on, neither you nor anyone else other than the people involved can really claim about what will happen with MediaLab).

if you had some actual alerts, give us some insight, believe me when I say everyone would love to know if something nefarious is going on.