User blog comment:Visually/Don't do "Summer's Over Update" before claim your mastery rewards./@comment-178.132.219.227-20151008135955/@comment-26536836-20151008141950

Unfortunately so.

Of course, we can't predict future or what gameloft will really do.

But updates of Android, iOS, Windows, they exactly same update so I think Gameloft will do same thing--reduced(or removed) mastery reward.

I tried to spend all the upgrades which was reduced. But I just found out(I just updated in Android) that there has more, it seems.

Other than upgrades, you can just claim them and use it later. So it will be fine.