Alternatively, it extends the reach of companies further into the home environment, and may exacerbate the existing trend for people not to switch off, which in turn makes it harder to achieve a good life-work balance. Imagine having a pressurised call-centre type role from home. Some people may feel greater pressure to appear 'corporate' in the home environment, others might not mind their kids or cats interrupting a Zoom meeting. Not everyone can create a suitable WFH environment in a nice spare room.
Whether this actually happens depends on corporate culture, the personalities and goals of the managers and employees, whether a crunch is on, and many other factors. But I'm not convinced that a tighter integration between work and home is necessarily always going to be a positive, from a mental health perspective.