Even though they lost Acuna to a season ACL injury, at least the Braves went out and did something. Guys like Soler, Rosario and Pederson were having down years, which made them easier to acquire. Like you said they had track records of being successful before. Adding them to the mix was better than just keeping the status quo, which is likely what this Jays front office would have done in that situation.
The NL East that season was pretty weak and the Braves despite sitting at 44-45 were only 4.5GB behind the first place Mets. AA definitely made a calculated gamble, and it paid off.
The 2021 Braves team was still pretty solid offensively:
Riley: 5.1 WAR
Freeman: 4.7 WAR
Albies: 3.7 WAR
Swanson: 3.3 WAR
Add in bats like Soler, Rosario, Duvall and Pederson, definitely helped with the loss of Acuna.
On the pitching side, the Braves didn't look as good actually. Morton and Fried were their two top arms, along with Ian Anderson, Huascar Ynoa and Drew Smyly. Wasn't as strong of a rotation as we saw from them in 2022 and 2023. Bullpen wise, they had some solid years from Minter, Matzek and Luke Jackson. Will Smith, off the top of my head, I think was dominant in the Postseason I recall.
Regardless, I would rather have a front office that is proactive. I don't think you should discredit AA at all during the 2021 season.