As a casual gamer, I would like to filter opponents in non ranked games based on certain play styles, given I absolutely despise some styles
I absolutely despise playing against several play styles. Specifically control decks or other decks that meta-game rather than actually game (i.e. mill decks, decks built around revealing your opponents hand and forcing them to discard all their cards, etc.).
When playing in non-ranked games, it would be nice if you could apply filters to the engine that matches players. In this way, when purely playing a game for "fun", I can actually have fun, rather than rage quitting the game because the opposing player decided to play a style that effectively prevents me from playing magic.
The filters could be based on common play styles, such as control, aggro, combo, etc. There could be an algorithm that analyzes the cards in your deck and assigns a rating to the deck in each of the styles based on the contents of the deck. A deck would be assigned one or more styles if the ranking of the style exceeds a certain score threshold.
The user could specify the filters during the game setup if and only if the game does not count as a ranked game or other event game (i.e. brawl or "Play" games).
The scheduler that matches opponents could include the user's preferred game filters when matching up players.
I believe this would improve the gaming experience for most players that are interesting in simply "having fun" while playing Arena, as they would be matched with similar players, with similar interests.
I understand that this feature would not make sense for ranked or event games given that these are actually linked to the game economy and it does not make sense to allow plays to attempt the "game the economy"; however, I believe this makes a lot of sense for the "for fun" games.
I could see there being a rule that stipulates that you cannot play a style that you are filtering (i.e. you cannot play a control deck if you are filtering out other control decks); however, I can also see a counter-point to this rule in that you may be tuning a control deck and want to play test it against non-control decks for a while.
So long as the filtering is reciprocal I don't see any issues with allowing this feature (i.e. having a negative impact on the gaming ecosystem). It would be equitable amongst all players.
It may end up causing some play styles to become unplayable in non-ranked games (e.g. "I love playing against control decks" ... said no one ever), if nearly all "for fun" players filter them out; however, some of these styles really only make sense in tournament/ranked play areas and really have no place in casual gaming, imo. Of course, that's my opinion. The nice thing about this feature is that no one player is dictating what decks you can play, they're just opting out of playing with you (similar to auto-conceding the moment you see the commander is a control commander).