I know for certain categories, this makes sense. Getting trophy milestones in the main categories should not have any money spent, to make the playing field even. Match victories, and other items like that, should have clarification on them, as in those contexts, an account that is old might have maxed progression as a F2P, (maybe not after this current update), but it is possible. Match Victories has my biggest gripe with that rule.

I think for these categories like Match Victory or Training Cave, it does not really matter whether you are Free-to-Play or not. Since these do not involve creating a new account, I do not think a Pay-to-Play account would be invalidated.