The only thing they had to do was making current runes free.
The thing that made LoL better than any other MOBA is that you could play your character however the hell you wanted to.
Sejuani AP? Mordekaiser AS? Nasus AP? Why not. And while some of these might be considered "troll", there were actual options like tankifying a non-tank character, buffing your mana regen to spam in lane or boosting your early AP/AD to help you grab early kills.
Sure a lot were niche builds but I loved playing Karma as literally every role/lane in the game. Tank AP, AD AS, Jungle offtank AP etc.
With the new system it looks like things like that are going to be impossible or at least severely damaged.
That is what made the game fun. You could find an AP Shaco or a full movement speed Nasus, and while most people just looked up some rune guide on the internet, there were actual options to play with.
I played Smite and the moment I noticed you couldn't buy AP items for an AD champion and vice versa I bailed out.
Now in regards to the filter thing. Whoever asked for the removal of a role filter? It's immensely more open than a position filter which tells you exactly what is the meta in a particular lane and is going to make people call others trolls because they're not picking whatever is in the stupid filter at the time.
Everything points towards them simplifying things god knows why. Maybe because Overwatch is eating their lunch, and that game is as simple as "go to the chokepoint and vomit all your abilities", but you know what? It's also as shallow as an ARAM match, so please find a better role model because LoL is better than that casual garbo.