If 5e still uses a map and position-based, round-based tactical combat, some kind of AoO analog is necessary. Otherwise, there would be no way of blocking passage or defending someone.
I'd be perfectly fine if they just got rid of map and/or rounds, removing the need for opportunity attacks. But I'm afraid that's not going to happen.
If AoOs stay, I'd prefer them to work differently than in 3e or 4e. If moving or casting a spell makes you vulnerable and provokes an attack than being prone, or stunned, or held, or unconscious should too. Opportunity attacks being reactions to something the enemy does, as opposed to exploiting the state he is in, is hard to accept for me.
I'd be perfectly fine if they just got rid of map and/or rounds, removing the need for opportunity attacks. But I'm afraid that's not going to happen.
If AoOs stay, I'd prefer them to work differently than in 3e or 4e. If moving or casting a spell makes you vulnerable and provokes an attack than being prone, or stunned, or held, or unconscious should too. Opportunity attacks being reactions to something the enemy does, as opposed to exploiting the state he is in, is hard to accept for me.