Confirming the above replies! You don't have to re-test as long as you keep your CPEs up to date and pay your AMF each year. If you do that, your cert will renew to another 3 year cycle and you'll get a new kit in the mail, and your digital cert online will update w/a new "expiration date" - but again, that date only applies if you don't keep up w/the membership requirements.
NO PLANS to change that from HQ.
PDI is a great way to earn CPEs on your own time, and with good, relevant content. Lots of courses to choose from and even more coming. https://www.isc2.org/development