Why do you think it will come? Promoted tweets can already be repositioned within the feed, there is no need to annoy users by deleting tweets that they want to read, that will simply reduce attention available for advertisers.

Why would Twitter throw away the user goodwill and financial success earned from a multi-year rollout of promoted tweets, by settling for a simplistic pay-to-play protection scheme to extract money from advertisers?

The OP article explains in detail how Weil has focused on targeting to improve relevance and engagement. Such targeting depends on data, which depends on an explicit interest graph. It would make no sense for Twitter to destroy the asset that provides signal to the ad biz.