I’ve not worked with a marketing team where that would work, but maybe it will for some.

I've never been anywhere that I thought it would work, but it ultimately did, almost everywhere.

I've found it takes a few iterations, but the marketing folks in on it love being the ones who actually can reliably deliver on their promises.

It doesn't work for the marketers that promise whatever they please without talking to dev, but I don't find them to be worthwhile professional allies, so I don't sweat it.

It doesn’t change the “massive customer will only renew if” scenario, though.

Very true. It doesn't help with that case, and that one does happen. I've had the best luck saying "we don't do that, but we're scrambling to add it" in that situation.