I believe a traditional chorus has a vocal, plus a musical release of tension - for the most part. There are exceptions.
The problem with labeling the section that happens before the drop a “chorus” is that harmonically and rhythmically, that is the section where all of the tension is built, not released. It is a transitional section that builds tension in order to work you up to wanting a release. Sure, the melody and vocal sound “chorus-like” because it has a singable hook, but the overriding function of that section is to build tension. Guess which section of a song typically has that primary duty? The pre-chorus. The function of a pre-chorus is to transition you to the chorus - that moment of release.
Is it possible to to have a pre-chorus without a chorus? Technically no. I think that’s why we’re subconsciously confused right now as we’re transitioning out of this model.
In this particular situation, if we’re going to label it either a “pre-chorus” or “chorus,” I think both are fundamentally wrong. But if I’m going to pick the lesser of two evils, this section functions emotionally like a pre-chorus. It’s a tension builder. I cannot in good conscience label it a chorus. I would much prefer we just label it a “build+instrumental break.”
Food for thought, anyway. Just my opinion. I am currently working on a more academic version of this argument.
