I'm not even clear on what it means, technical debt is non-deterministic in many cases.

To say it differently: if you wrote code that was perfect in time 0, that code may become legacy in time 100.

Are they saying you should continuously refactor all your code to cover the 'current user needs'?

I just think it's an oversimplification for those cases where you don't mind not covering the 0,001% of use cases.

Even if it is, it sounds highly ineffective, unless the only value you are delivering is source code.