If you run a membership that has multiple payment frequencies (e.g. a monthly and annual payment option) but only one tier, the product page will now automatically enumerate those payment frequencies for your customers to select.
Why did we do this? Simple: conversion rate optimization. The easier it is to find the option someone wants — and the fewer clicks it takes — the more likely they are to make a purchase. By showing all billing period options on single-tier memberships, we save your customers a click, yet another incremental improvement to conversion rates site-wide.
Memberships with multiple tiers retain the payment frequency selector and default frequency setting. Showing too many options at once can overwhelm a customer (a paradox of choice), so memberships with multiple tiers stick with the previous behavior.