We learned at the end of 2020 that Overwatch is at its best when it's constantly updated and always feeling fresh. The patch cadence was never faster than it was at the end of 2020, and the game felt amazing.
In my opinion, 6v6 won't work unless the patch cadence speeds up to what it was back then. 6v6 means long DPS queue times, and was unbearable at the end of OW1. If OW2 want looming around the corner back then, the game would have died. The fast patch cadence keeping the game fresh somewhat makes up for the 10, 15, 20 minute queue times.
That being said, the current implementation of 5v5 misses the mark as well. DPS and Support players are somewhat spoiled with 5v5, both with queue times and gameplay. But the Tank role suffers mightily. Over the years the game and hero design philosophy has shifted to be dependent on 2 tanks being able to soak up enemy cooldowns, cover for each other, and protect the team. Putting all that responsibility on one player sucks.
Aaron's blog post makes me hopeful that they're gonna try stuff beyond 1-2-2 5v5 versus 2-2-2 6v6 though, which is exciting. I don't envy the dev team because this is an incredibly difficult problem to solve, but it seems like they're willing to get more creative about trying to solve it than they have been in the past, which is nice.