He has said in interviews after winning his two gold medal that he's going to try to stop, but since he tried that two times before, there's a 20% chance he'll be back.

He also said he doesn't know what he's going to do the next few years, but that there are a few ultra runs he still wants to do.

Here is a source. It's in Dutch though and doesn't mention the 20% https://www.nu.nl/olympische-spelen/6183560/van-der-poel-kie...