Interesting that this is the conclusion you've come to, because I've heard from some colleagues that this is actually the correct approach for management to take. Their argument would be that either way, to accommodate the new functionality, the codebase would have to be refactored. And if it is refactored proactively, well that will probably be in a way not compatible with the future design, because you can't anticipate something you know nothing about.

So it's a matter of 1 vs 2 refactors, and the management chose one by delaying as long as possible.