Can't speak for the company and their intention - but here's how I'd answer that question, authentically to me:

"Work is variable. If we are on a super tight deadline with real implications, then people should put in extra hours if they can. Like, if we need to deliver for a major client, let's just do that.

And then other times, you can back off and work at a sustainable pace. It really depends on what makes sense in the situation"

This answer may not please everyone but I think it would resonate with reasonable people. It's worked well for me.