This is an expression I have used for many years, it is just a metaphor for never throwing out an idea, leave it available for scrutiny later when you know more, or for parts to build something different, or just for inspiration when building the portfolio of projects
The brainiacs in Silicon Valley have now come up with a better expression, “Strategic Pivot” which is essentially the same thing, but geared specifically to innovation in the digital world. Perhaps unfortunately for silicon valley, not every innovation is a new app, most are far more mundane.
A new way of moving a product WIP from one production station to the next can be an innovation, as can an improvement in the process of collecting data on that movement, and further improving it by removing excess time and effort.
In either case, the metaphor, whichever one you choose, works. Never throw out an idea, just because you cannot see the value now.