I don't think so. Why would they stop getting their writers to do their marketing for them? In fact, I'm surprised it took them this long to set up a referral program. It's an excellent business tactic: lure your own customers into doing your marketing for you.

The fact that the referral links mildly irritate some people won't be enough for them to stop it. After all, I doubt anybody is leaving Medium because of the referral links. The decision will be all about the numbers. I've only been here a few months, and I've already got 3 referrals. Imagine how many referrals people with more reach can get. It would be a form of business suicide for Medium to suddenly get rid of that.