Blocked or not I don't see how the Google Play Store would know and take action to stop you from downloading the app. It probably has more to do with your device being 8 years old, running what version of Android? Anyway Snap likely updated their app and stopped supporting your version of Android or your device's hardware. You could check with the Snap devs through the Contact Us link in the app store and just ask if Android version(whatever you're running) and 6Edge + are still supported, then mention the issue you're having at the Play Store downloading and installing the app. I wouldn't go into all of the rest of it as that is TMI just know if you can install the app.
In the meantime there is a good chance if you had not uninstalled the app it would still be working on your device. A lot of the time even if an app is no longer supported by its devs the app continues to function but once uninstalled can't be recovered.
Good luck with support but it may be time to upgrade devices if it is very important to you.