Honestly, I’m still curious how that’s gonna play out. Lots of jingles weren’t the craziest of compositions so far. They’re often just a handful of notes played in succession with one instrument. That’s a big part of what makes them memorable.

Instead, I feel like companies often paid for a composer, because they needed someone whose taste is decidedly more highly regarded than their design committee’s. Someone who’s able to make a decision without twenty people thinking they have a much better idea that needs to be heard.

So, I could imagine this going one way or another.
Either the boss can now generate jingles quickly enough that they don’t delegate it. Then the decision is still in the hands of one person, although likely the hands of someone with no musical training, so I do expect jingles to sound worse in that scenario.
…Or everyone in the design committee brings along a dozen generated jingles, the decision paralysis is magnitudes worse and they have to bring in a composer anyways.

The first wave of displacement was licensing - all those car commercials with Springsteen tunes.