Post-death activities does sound scary at first, but if you really think about it carefully and evaluate every perspective, it is actually surprisingly reasonable. Yeah, it doesn't make sense at the slightest from the realism perspective. But if Ubisoft's intent is to reduce the downtime of the game and keep players engaged, this would actually be the perfect solution.
Most people's fear of the change comes from Echo and Maestro, because at first glance it would make these two operators, and defenders as a whole extremely overpowered. But what people fail to realize is the fact that Echo and Maestro are about the only gadgets on defense that are actively controlled. Cameras, Black Eyes, etc. will remain as they are, completely unchanged.
The attacker side however is quite the contrary. Every single operator on attack has access to 2 drivable drones, which means they will be able to actively collect intel in a way more flexible and dedicated fashion post-death, which can massively impact the outcome of a round. This alone would be able to balance out the seemingly OP maestro and echo. Not to mention twitch, who will be able to destroy tons of defender utility post-death.
Now back to the topic of Echo and Maestro. First of all Echo is currently one of the weakest operators on defense due to the nerf to his drones. Maestro is also getting a massive nerf very soon where meleeing his cameras will black them out. So a boost in pick rate for these two operators wouldn't be nearly as bad as it sounds.
So as long as you have a deep enough understanding of the game, you'd realize that contrary to popular beliefs, post-death activities will actually benefit attackers way more than defenders, which is a good thing considering the fact that siege is ridiculously defender-sided. Post-death activities is a two-birds-with-one-stone solution to siege's defender-sided nature and its incredibly long downtime. I am all for it.