Is the team/company's engineering culture decent otherwise?
Ultimately, someone at the company wants to have software that makes them more money or keeps them from worrying about losing money or going to jail (compliance.
Someone at the company thinks they can improve the state of software maintenance/delivery by changing the process. Maybe this is a VP accommodating a micromanaging CEO and doing something so that they can be seen doing something, but it could also be a well-intentioned change, in which case they want either more productivity -- with the theory that more software sooner results in more value -- or more predictability, with the theory that managing teams more closely results in less surprises and delays.
Identifying the root motivation may help propose alternatives, so it may be worth talking 1-1 with someone in leadership to try to understand the motivation. "On team X we're going to move to 1 week sprints. For my contextual awareness to better help implement this change, are we primarily hoping to increase predictability, even if velocity ends up decreasing, or should we focus more on increasing velocity even if work ends up carrying over?"
I like focusing on the root motivation. I haven't been able to get to it based on previous conversations. It seems to be perceived velocity because of the increased visibility from what I've gathered but the fact that we don't even have the option to experiment leads to a bigger issue IMO. The teams just aren't empowered to adjust course.
See if your manager knows what's going on. They may be just as oppressed as you feel!
And they may be willing to go along with smaller secret team-level experiments. Maybe Kanban will result in even better visibility and performance! (And satisfaction)
Yeah, unfortunately I did and have been declined several times to experiment. I've also suggested Kanban too since it feels more in line with the pace and the lacking requirements and also shut down several times.
Do the experiment at the smallest level possible. And if not, it's time to suck it up or find a new job.