Kratom is an opioid in the sense that it is a partial mu opiate receptor agonist so you will still go through some sort of opiate WD once it is time to get off of the Kratom, albeit most likely less so than if you were WDing from a "harder" opiate such as H or even subs depending on the amount and strength of Kratom you take. I never really messed with opiates recreationally, instead I used Kratom to get off of Benzos not realizing it worked on the opiate receptors. While it worked like a godsend for getting off the Xanax, I am now completely dependent on Kratom and go through terrible WD every morning upon waking up before I dose for the day. The strain I have been using these past few years is a plain leaf/extract mix, it is extremely potent and my doses have been very high. As a matter of fact I have been considering going on Suboxone just to get myself off of the Kratom itself. Usually I would tell people to just suck it up for a week and deal with the fairly mild Kratom WD as I heard kicking subs are much harder, but the stuff I am on is so powerful and absurd that I would never make it without either having to go to detox or taking at least a week off from work while hopefully finding some comfort meds for that specific week.
Edit: Don't let this post scare you. I have heard of many people who successfully used Kratom to get off of subs and even H. I would just recommend that if you go down the Kratom route, order something not super potent, never up your dose and stay on it for the shortest time period you possibly can.