Preetam De has recently introduced XDE, and I must admit there are likeable parts to notice, for example the focus on 1 Rule Framework (work on one thing until done). One concern is that it does not place a high value on long-lived teams, which can create an eco-system where continuous improvement is difficult.
Thanks for creating this discussion thread, surprised to find it after 2 months of publishing it.
The idea of the short lived Bubbles is to promote awareness of shared (decoupled) responsibility among all existing teams. This disruptive and unstable format will increase the need of continuous refactoring which in turn exposes any architectural loopholes.
You are right in saying that continuous improvement is difficult in this ecosystem. For legacy codebases, it can even slow the development down. The benefit is, when we realise why we want to do it. We want to reduce technical debt as early as possible and as often as we can. Once the teams are used to it, it will become a second nature and help them adapt any situation and be agile.