I was on board with this (I'd love victorious graves but I took a break from the game during that season) until someone put it this way:
What if on league's 15 year anniversary, they released another anniversary skin, like an anniversary party Urgot or something. But, they let people choose whether they got Annieversary or the new skin.
People who were here for the 10 year anniversary would be like "wtf, I thought that was for supporting the game during 10 year anniversary?"
The victorious skins are a year-based thing. It's "hey you played decently during season _! here's a marker for that specific season. Thanks for supporting the game at that time!". It's unfair to the people who appreciate that sort of thing. The way it is now you can see Victorious Morg and be like "ooh okay, I see you long timer" and it's kinda nice.
Sad that I won't get that sweet graves skin and have to settle with pool party? Sure. But I get the decision they made.