The author describes the unhappy flow when there is nothing he wants to buy, he should have just stonewalled them or removed himself from the mailing list when the feature he needed is not there. If the feature is there and he want it, the story goes totally differently. But both cases are going to start with a call. The big mistake here is taking the call or giving sales a whiff of your interest given the volume/commission model, a smart salesperson (unfortunately somewhat rare) is going to simply move on, saving time on both sides.

A more happy flow exists, author signs up for trial, he can't find or is unsure if feature exists during trial or reading docs, he asks sales/sales engineer where it is, salespeople show him or speak to PM to get him a timeline, later the feature he needs goes into beta and sales reconnects and demos, starts trial using beta. Sales helps draft the internal proposal/implementation plan to convince his boss and the hundreds of others needed for the sale. They buy when it goes GA.